diff --git a/ebook_converter/ebooks/conversion/cli.py b/ebook_converter/ebooks/conversion/cli.py
index 77fc0eb..2602467 100644
--- a/ebook_converter/ebooks/conversion/cli.py
+++ b/ebook_converter/ebooks/conversion/cli.py
@@ -12,7 +12,7 @@ import re
 import sys
 
 from ebook_converter.utils.config import OptionParser
-from ebook_converter.utils.logging import Log
+from ebook_converter.utils import logging
 from ebook_converter.customize.conversion import OptionRecommendation
 
 
@@ -66,7 +66,7 @@ def check_command_line_options(parser, args, log):
     if (not input_file.endswith('.recipe') and
             not os.access(input_file, os.R_OK) and
             not ('-h' in args or '--help' in args)):
-        log.error('Cannot read from', input_file)
+        log.error('Cannot read from %s', input_file)
         raise SystemExit(1)
     if input_file.endswith('.recipe') and not os.access(input_file, os.R_OK):
         input_file = args[1]
@@ -267,7 +267,7 @@ class ProgressBar(object):
     def __call__(self, frac, msg=''):
         if msg:
             percent = int(frac*100)
-            self.log('%d%% %s' % (percent, msg))
+            self.log.info('%d%% %s' % (percent, msg))
 
 
 def create_option_parser(args, log):
@@ -275,20 +275,18 @@ def create_option_parser(args, log):
         from ebook_converter.constants_old import __appname__
         from ebook_converter.constants_old import __author__
         from ebook_converter.constants_old import __version__
-        log(os.path.basename(args[0]), '('+__appname__, __version__+')')
-        log('Created by:', __author__)
+        log.info("%s (%s, %s)", os.path.basename(args[0]), __appname__,
+                 __version__)
+        log.info('Created by: %s', __author__)
         raise SystemExit(0)
     if '--list-recipes' in args:
         from ebook_converter.web.feeds.recipes.collection import \
                 get_builtin_recipe_titles
-        log('Available recipes:')
+        log.info('Available recipes:')
         titles = sorted(get_builtin_recipe_titles())
         for title in titles:
-            try:
-                log('\t'+title)
-            except Exception:
-                log('\t'+repr(title))
-        log('%d recipes available' % len(titles))
+            log.info('\t%s', title)
+        log.info('%d recipes available', len(titles))
         raise SystemExit(0)
 
     parser = option_parser()
@@ -352,7 +350,7 @@ def read_sr_patterns(path, log=None):
 
 
 def main(args=sys.argv):
-    log = Log()
+    log = logging.default_log
     mimetypes.init([pkg_resources.resource_filename('ebook_converter',
                                                     'data/mime.types')])
     parser, plumber = create_option_parser(args, log)
@@ -386,7 +384,7 @@ def main(args=sys.argv):
 
     plumber.run()
 
-    log('Output saved to', ' ', plumber.output)
+    log.info('Output saved to %s', plumber.output)
 
     return 0
 
diff --git a/ebook_converter/ebooks/conversion/plugins/epub_input.py b/ebook_converter/ebooks/conversion/plugins/epub_input.py
index 73196e3..37a9afe 100644
--- a/ebook_converter/ebooks/conversion/plugins/epub_input.py
+++ b/ebook_converter/ebooks/conversion/plugins/epub_input.py
@@ -146,7 +146,7 @@ class EPUBInput(InputFormatPlugin):
             if len(spine) > 1:
                 for item in spine:
                     if item.get('idref') == titlepage_id:
-                        log('Found HTML cover', titlepage_href)
+                        log.info('Found HTML cover %s', titlepage_href)
                         if self.for_viewer:
                             item.attrib.pop('linear', None)
                         else:
@@ -192,7 +192,7 @@ class EPUBInput(InputFormatPlugin):
         elem = [x for x in manifest if x.get('id', '') == idref]
         if not elem or elem[0].get('href', None) != guide_cover:
             return
-        log('Found HTML cover', guide_cover)
+        log.info('Found HTML cover %s', guide_cover)
 
         # Remove from spine as covers must be treated
         # specially
@@ -272,8 +272,8 @@ class EPUBInput(InputFormatPlugin):
             zf = ZipFile(stream)
             zf.extractall(os.getcwd())
         except Exception:
-            log.exception('EPUB appears to be invalid ZIP file, trying a'
-                          ' more forgiving ZIP parser')
+            log.exception('EPUB appears to be invalid ZIP file, trying a '
+                          'more forgiving ZIP parser')
             from ebook_converter.utils.localunzip import extractall
             stream.seek(0)
             extractall(stream)
diff --git a/ebook_converter/ebooks/conversion/plugins/epub_output.py b/ebook_converter/ebooks/conversion/plugins/epub_output.py
index fe87c2d..e3d1b20 100644
--- a/ebook_converter/ebooks/conversion/plugins/epub_output.py
+++ b/ebook_converter/ebooks/conversion/plugins/epub_output.py
@@ -214,8 +214,8 @@ class EPUBOutput(OutputFormatPlugin):
         self.workaround_sony_quirks()
 
         if self.oeb.toc.count() == 0:
-            self.log.warn('This EPUB file has no Table of Contents. '
-                    'Creating a default TOC')
+            self.log.warning('This EPUB file has no Table of Contents. '
+                             'Creating a default TOC')
             first = next(iter(self.oeb.spine))
             self.oeb.toc.add('Start', first.href)
 
@@ -229,7 +229,7 @@ class EPUBOutput(OutputFormatPlugin):
         encrypted_fonts = getattr(input_plugin, 'encrypted_fonts', [])
 
         if _uuid is None:
-            self.log.warn('No UUID identifier found')
+            self.log.warning('No UUID identifier found')
             _uuid = str(uuid.uuid4())
             oeb.metadata.add('identifier', _uuid, scheme='uuid', id=_uuid)
 
@@ -281,7 +281,7 @@ class EPUBOutput(OutputFormatPlugin):
                 os.mkdir(opts.extract_to)
                 with ZipFile(output_path) as zf:
                     zf.extractall(path=opts.extract_to)
-                self.log.info('EPUB extracted to', opts.extract_to)
+                self.log.info('EPUB extracted to %s', opts.extract_to)
 
     def upgrade_to_epub3(self, tdir, opf):
         self.log.info('Upgrading to EPUB 3...')
@@ -323,7 +323,7 @@ class EPUBOutput(OutputFormatPlugin):
                 if not os.path.exists(path):
                     uris.pop(uri)
                     continue
-                self.log.debug('Encrypting font:', uri)
+                self.log.debug('Encrypting font: %s', uri)
                 with open(path, 'r+b') as f:
                     data = f.read(1024)
                     if len(data) >= 1024:
@@ -332,7 +332,7 @@ class EPUBOutput(OutputFormatPlugin):
                         f.write(bytes(bytearray(data[i] ^ key[i%16]
                                                 for i in range(1024))))
                     else:
-                        self.log.warn('Font', path, 'is invalid, ignoring')
+                        self.log.warning('Font %s is invalid, ignoring', path)
                 if not isinstance(uri, str):
                     uri = uri.decode('utf-8')
                 fonts.append('''
@@ -385,8 +385,9 @@ class EPUBOutput(OutputFormatPlugin):
                 _base, _, frag = href.partition('#')
                 frag = urllib.parse.unquote(frag)
                 if frag and frag_pat.match(frag) is None:
-                    self.log.warn(
-                            'Removing fragment identifier %r from TOC as Adobe Digital Editions cannot handle it'%frag)
+                    self.log.warning('Removing fragment identifier %r from '
+                                     'TOC as Adobe Digital Editions cannot '
+                                     'handle it', frag)
                     node.href = _base
 
         for x in self.oeb.spine:
@@ -530,8 +531,8 @@ class EPUBOutput(OutputFormatPlugin):
                     for x in self.oeb.spine:
                         if x.href == href:
                             if frag_is_at_top(x.data, frag):
-                                self.log.debug('Removing anchor from TOC href:',
-                                        href+'#'+frag)
+                                self.log.debug('Removing anchor from TOC '
+                                               'href: %s#%s', href, frag)
                                 toc.href = href
                             break
             for x in toc:
diff --git a/ebook_converter/ebooks/conversion/plugins/lrf_input.py b/ebook_converter/ebooks/conversion/plugins/lrf_input.py
index 6f51f98..b5154b0 100644
--- a/ebook_converter/ebooks/conversion/plugins/lrf_input.py
+++ b/ebook_converter/ebooks/conversion/plugins/lrf_input.py
@@ -20,7 +20,7 @@ class LRFInput(InputFormatPlugin):
         from ebook_converter.ebooks.lrf.input import MediaType, Styles, \
                 TextBlock, Canvas, ImageBlock, RuledLine
         self.log = log
-        self.log('Generating XML')
+        self.log.info('Generating XML')
         from ebook_converter.ebooks.lrf.lrfparser import LRFDocument
         d = LRFDocument(stream)
         d.parse()
@@ -50,7 +50,7 @@ class LRFInput(InputFormatPlugin):
                 if imgstr:
                     plot_map[ro] = imgstr[0].get('file')
 
-        self.log('Converting XML to HTML...')
+        self.log.info('Converting XML to HTML...')
 
         with open(pkg_resources.
                   resource_filename('ebook_converter',
diff --git a/ebook_converter/ebooks/conversion/plumber.py b/ebook_converter/ebooks/conversion/plumber.py
index 76ef6be..06553a6 100644
--- a/ebook_converter/ebooks/conversion/plumber.py
+++ b/ebook_converter/ebooks/conversion/plumber.py
@@ -854,8 +854,8 @@ OptionRecommendation(name='search_replace',
                     try:
                         val = float(val)
                     except ValueError:
-                        self.log.warn('Values of series index and rating must'
-                                      ' be numbers. Ignoring', val)
+                        self.log.warning('Values of series index and rating '
+                                         'must be numbers. Ignoring %s', val)
                         continue
                 elif x in ('timestamp', 'pubdate'):
                     try:
@@ -882,8 +882,8 @@ OptionRecommendation(name='search_replace',
         self.opts_to_mi(mi)
         if mi.cover:
             if mi.cover.startswith('http:') or mi.cover.startswith('https:'):
-                self.log.warn("TODO: Cover image is on remote server, "
-                              "implement downloading using requests")
+                self.log.warning("TODO: Cover image is on remote server, "
+                                 "implement downloading using requests")
             ext = mi.cover.rpartition('.')[-1].lower().strip()
             if ext not in ('png', 'jpg', 'jpeg', 'gif'):
                 ext = 'jpg'
@@ -909,8 +909,8 @@ OptionRecommendation(name='search_replace',
                 if x.short_name == sval:
                     setattr(self.opts, attr, x)
                     return
-            self.log.warn(
-                'Profile (%s) %r is no longer available, using default'%(which, sval))
+            self.log.warning('Profile (%s) %r is no longer available, using '
+                             'default', which, sval)
             for x in profiles():
                 if x.short_name == 'default':
                     setattr(self.opts, attr, x)
@@ -925,14 +925,16 @@ OptionRecommendation(name='search_replace',
         if self.opts.verbose:
             self.log.filter_level = self.log.DEBUG
         if self.changed_options:
-            self.log('Conversion options changed from defaults:')
+            self.log.info('Conversion options changed from defaults:')
             for rec in self.changed_options:
                 if rec.option.name not in ('username', 'password'):
-                    self.log(' ', '%s:' % rec.option.name, repr(rec.recommended_value))
+                    self.log.info(' %s', rec.option.name,
+                                  repr(rec.recommended_value))
         if self.opts.verbose > 1:
             self.log.debug('Resolved conversion options')
             try:
-                self.log.debug('ebook_converter version:', constants.VERSION)
+                self.log.debug('ebook_converter version: %s',
+                               constants.VERSION)
                 odict = dict(self.opts.__dict__)
                 for x in ('username', 'password'):
                     odict.pop(x, None)
@@ -968,7 +970,7 @@ OptionRecommendation(name='search_replace',
                 self.input_plugin.save_download(zf)
             zf.close()
 
-        self.log.info('Input debug saved to:', out_dir)
+        self.log.info('Input debug saved to: %s', out_dir)
 
     def run(self):
         '''
@@ -1022,7 +1024,8 @@ OptionRecommendation(name='search_replace',
             from ebook_converter.ebooks.azw4.reader import unwrap
             unwrap(stream, self.output)
             self.ui_reporter(1.)
-            self.log(self.output_fmt.upper(), 'output written to', self.output)
+            self.log.info('%s output written to %s', self.output_fmt.upper(),
+                          self.output)
             self.flush()
             return
 
@@ -1056,7 +1059,7 @@ OptionRecommendation(name='search_replace',
             if self.opts.debug_pipeline is not None:
                 out_dir = os.path.join(self.opts.debug_pipeline, 'parsed')
                 self.dump_oeb(self.oeb, out_dir)
-                self.log('Parsed HTML written to:', out_dir)
+                self.log.info('Parsed HTML written to: %s', out_dir)
             self.input_plugin.specialize(self.oeb, self.opts, self.log,
                     self.output_fmt)
 
@@ -1105,13 +1108,13 @@ OptionRecommendation(name='search_replace',
             try:
                 fkey = list(map(float, fkey.split(',')))
             except Exception:
-                self.log.error('Invalid font size key: %r ignoring'%fkey)
+                self.log.error('Invalid font size key: %s ignoring', fkey)
                 fkey = self.opts.dest.fkey
 
         if self.opts.debug_pipeline is not None:
             out_dir = os.path.join(self.opts.debug_pipeline, 'structure')
             self.dump_oeb(self.oeb, out_dir)
-            self.log('Structured HTML written to:', out_dir)
+            self.log.info('Structured HTML written to: %s', out_dir)
 
         if self.opts.extra_css and os.path.exists(self.opts.extra_css):
             with open(self.opts.extra_css, 'rb') as f:
@@ -1187,9 +1190,9 @@ OptionRecommendation(name='search_replace',
         if self.opts.debug_pipeline is not None:
             out_dir = os.path.join(self.opts.debug_pipeline, 'processed')
             self.dump_oeb(self.oeb, out_dir)
-            self.log('Processed HTML written to:', out_dir)
+            self.log.info('Processed HTML written to: %s', out_dir)
 
-        self.log.info('Creating %s...'%self.output_plugin.name)
+        self.log.info('Creating %s...', self.output_plugin.name)
         our = CompositeProgressReporter(0.67, 1., self.ui_reporter)
         self.output_plugin.report_progress = our
         our(0., 'Running %s plugin' % self.output_plugin.name)
@@ -1200,7 +1203,8 @@ OptionRecommendation(name='search_replace',
         self.ui_reporter(1.)
         run_plugins_on_postprocess(self.output, self.output_fmt)
 
-        self.log(self.output_fmt.upper(), 'output written to', self.output)
+        self.log.info('%s output written to %s', self.output_fmt.upper(),
+                      self.output)
         self.flush()
 
 
@@ -1230,7 +1234,7 @@ def create_oebbook(log, path_or_stream, opts, reader=None,
     if specialize is not None:
         oeb = specialize(oeb) or oeb
     # Read OEB Book into OEBBook
-    log('Parsing all content...')
+    log.info('Parsing all content...')
     oeb.removed_items_to_ignore = removed_items
     if reader is None:
         from ebook_converter.ebooks.oeb.reader import OEBReader
@@ -1241,11 +1245,11 @@ def create_oebbook(log, path_or_stream, opts, reader=None,
 
 
 def create_dummy_plumber(input_format, output_format):
-    from ebook_converter.utils.logging import Log
+    from ebook_converter.utils import logging
     input_format = input_format.lower()
     output_format = output_format.lower()
     output_path = 'dummy.'+output_format
-    log = Log()
+    log = logging.default_log
     log.outputs = []
     input_file = 'dummy.'+input_format
     if input_format in ARCHIVE_FMTS:
diff --git a/ebook_converter/ebooks/conversion/utils.py b/ebook_converter/ebooks/conversion/utils.py
index b9af3f9..2035148 100644
--- a/ebook_converter/ebooks/conversion/utils.py
+++ b/ebook_converter/ebooks/conversion/utils.py
@@ -5,11 +5,6 @@ from ebook_converter.utils.logging import default_log
 from ebook_converter.utils.wordcount import get_wordcount_obj
 
 
-__license__ = 'GPL v3'
-__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
 class HeuristicProcessor(object):
 
     def __init__(self, extra_opts=None, log=None):
@@ -50,8 +45,8 @@ class HeuristicProcessor(object):
         title = match.group('title')
         if not title:
             self.html_preprocess_sections = self.html_preprocess_sections + 1
-            self.log.debug("marked " + str(self.html_preprocess_sections) +
-                    " chapters. - " + str(chap))
+            self.log.debug("marked %s chapters. - %s",
+                           self.html_preprocess_sections, str(chap))
             return '<h2>'+chap+'</h2>\n'
         else:
             delete_whitespace = re.compile('^\\s*(?P<c>.*?)\\s*$')
@@ -59,16 +54,16 @@ class HeuristicProcessor(object):
             txt_chap = delete_quotes.sub('', delete_whitespace.sub('\\g<c>', html2text(chap)))
             txt_title = delete_quotes.sub('', delete_whitespace.sub('\\g<c>', html2text(title)))
             self.html_preprocess_sections = self.html_preprocess_sections + 1
-            self.log.debug("marked " + str(self.html_preprocess_sections) +
-                    " chapters & titles. - " + str(chap) + ", " + str(title))
+            self.log.debug("marked %s chapters & titles. - %s, %s",
+                           self.html_preprocess_sections, chap, title)
             return '<h2 title="'+txt_chap+', '+txt_title+'">'+chap+'</h2>\n<h3 class="sigilNotInTOC">'+title+'</h3>\n'
 
     def chapter_break(self, match):
         chap = match.group('section')
         styles = match.group('styles')
         self.html_preprocess_sections = self.html_preprocess_sections + 1
-        self.log.debug("marked " + str(self.html_preprocess_sections) +
-                " section markers based on punctuation. - " + str(chap))
+        self.log.debug("marked %s section markers based on punctuation. - %s",
+                       self.html_preprocess_sections, chap)
         return '<'+styles+' style="page-break-before:always">'+chap
 
     def analyze_title_matches(self, match):
@@ -111,8 +106,6 @@ class HeuristicProcessor(object):
         line_end = line_end_ere.findall(raw)
         tot_htm_ends = len(htm_end)
         tot_ln_fds = len(line_end)
-        # self.log.debug("There are " + str(tot_ln_fds) + " total Line feeds, and " +
-        #        str(tot_htm_ends) + " marked up endings")
 
         if percent > 1:
             percent = 1
@@ -120,7 +113,6 @@ class HeuristicProcessor(object):
             percent = 0
 
         min_lns = tot_ln_fds * percent
-        # self.log.debug("There must be fewer than " + str(min_lns) + " unmarked lines to add markup")
         return min_lns > tot_htm_ends
 
     def dump(self, raw, where):
@@ -148,7 +140,6 @@ class HeuristicProcessor(object):
         return wordcount.words
 
     def markup_italicis(self, html):
-        # self.log.debug("\n\n\nitalicize debugging \n\n\n")
         ITALICIZE_WORDS = [
             'Etc.', 'etc.', 'viz.', 'ie.', 'i.e.', 'Ie.', 'I.e.', 'eg.',
             'e.g.', 'Eg.', 'E.g.', 'et al.', 'et cetera', 'n.b.', 'N.b.',
@@ -178,7 +169,6 @@ class HeuristicProcessor(object):
         for pat in ITALICIZE_STYLE_PATS:
             for match in re.finditer(pat, search_text):
                 ital_string = str(match.group('words'))
-                # self.log.debug("italicising "+str(match.group(0))+"    with <i>"+ital_string+"</i>")
                 try:
                     html = re.sub(re.escape(str(match.group(0))), '<i>%s</i>' % ital_string, html)
                 except OverflowError:
@@ -205,10 +195,11 @@ class HeuristicProcessor(object):
             if wordcount > 200000:
                 typical_chapters = 15000.
             self.min_chapters = int(ceil(wordcount / typical_chapters))
-        self.log.debug("minimum chapters required are: "+str(self.min_chapters))
+        self.log.debug("minimum chapters required are: %s", self.min_chapters)
         heading = re.compile('<h[1-3][^>]*>', re.IGNORECASE)
         self.html_preprocess_sections = len(heading.findall(html))
-        self.log.debug("found " + str(self.html_preprocess_sections) + " pre-existing headings")
+        self.log.debug("found %s pre-existing headings",
+                       self.html_preprocess_sections)
 
         # Build the Regular Expressions in pieces
         init_lookahead = "(?=<(p|div))"
@@ -298,7 +289,8 @@ class HeuristicProcessor(object):
                 if n_lookahead_req:
                     n_lookahead = re.sub("(ou|in|cha)", "lookahead_", full_chapter_line)
                 if not analyze:
-                    self.log.debug("Marked " + str(self.html_preprocess_sections) + " headings, " + log_message)
+                    self.log.debug("Marked %s headings, %s",
+                                   self.html_preprocess_sections, log_message)
 
                 chapter_marker = arg_ignorecase+init_lookahead+full_chapter_line+blank_lines+lp_n_lookahead_open+n_lookahead+lp_n_lookahead_close+ \
                     lp_opt_title_open+title_line_open+title_header_open+lp_title+title_header_close+title_line_close+lp_opt_title_close
@@ -311,11 +303,12 @@ class HeuristicProcessor(object):
                         if float(self.chapters_with_title) / float(hits) > .5:
                             title_req = True
                             strict_title = False
-                        self.log.debug(
-                                str(type_name)+" had "+str(hits)+
-                                " hits - "+str(self.chapters_no_title)+" chapters with no title, "+
-                                str(self.chapters_with_title)+" chapters with titles, "+
-                                str(float(self.chapters_with_title) / float(hits))+" percent. ")
+                        self.log.debug('%s had %s hits %s chapters with no '
+                                       'title, %s chapters with titles, %s '
+                                       'percent.', type_name, hits,
+                                       self.chapters_no_title,
+                                       self.chapters_with_title,
+                                       self.chapters_with_title / hits)
                         if type_name == 'common':
                             analysis_result.append([chapter_type, n_lookahead_req, strict_title, ignorecase, title_req, log_message, type_name])
                         elif self.min_chapters <= hits < max_chapters or self.min_chapters < 3 > hits:
@@ -332,8 +325,9 @@ class HeuristicProcessor(object):
         words_per_chptr = wordcount
         if words_per_chptr > 0 and self.html_preprocess_sections > 0:
             words_per_chptr = wordcount // self.html_preprocess_sections
-        self.log.debug("Total wordcount is: "+ str(wordcount)+", Average words per section is: "+
-                       str(words_per_chptr)+", Marked up "+str(self.html_preprocess_sections)+" chapters")
+        self.log.debug("Total wordcount is: %s, Average words per section "
+                       "is: %s, Marked up %s chapters", wordcount,
+                       words_per_chptr, self.html_preprocess_sections)
         return html
 
     def punctuation_unwrap(self, length, content, format):
@@ -427,7 +421,8 @@ class HeuristicProcessor(object):
         txtindent = re.compile(str(r'<(?P<tagtype>p|div)(?P<formatting>[^>]*)>\s*(?P<span>(<span[^>]*>\s*)+)?\s*(\u00a0){2,}'), re.IGNORECASE)
         html = txtindent.sub(self.insert_indent, html)
         if self.found_indents > 1:
-            self.log.debug("replaced "+str(self.found_indents)+ " nbsp indents with inline styles")
+            self.log.debug("replaced %s nbsp indents with inline styles",
+                           self.found_indents)
         return html
 
     def cleanup_markup(self, html):
@@ -475,8 +470,8 @@ class HeuristicProcessor(object):
         blanklines = self.blankreg.findall(html)
         lines = self.linereg.findall(html)
         if len(lines) > 1:
-            self.log.debug("There are " + str(len(blanklines)) + " blank lines. " +
-                    str(float(len(blanklines)) / float(len(lines))) + " percent blank")
+            self.log.debug("There are %s blank lines. %s percent blank",
+                           len(blanklines), len(blanklines) / len(lines))
 
             if float(len(blanklines)) / float(len(lines)) > 0.40:
                 return True
@@ -600,8 +595,8 @@ class HeuristicProcessor(object):
                         width = int(re.sub('.*?width(:|=)(?P<wnum>\\d+).*', '\\g<wnum>', replacement_break))
                     except:
                         scene_break = hr_open+'<hr style="height: 3px; background:#505050" /></div>'
-                        self.log.warn('Invalid replacement scene break'
-                                ' expression, using default')
+                        self.log.warning('Invalid replacement scene break'
+                                         ' expression, using default')
                     else:
                         replacement_break = re.sub('(?i)(width=\\d+\\%?|width:\\s*\\d+(\\%|px|pt|em)?;?)', '', replacement_break)
                         divpercent = (100 - width) // 2
@@ -702,20 +697,23 @@ class HeuristicProcessor(object):
                             blockquote_open_loop = blockquote_open
                         if debugabby:
                             self.log.debug('\n\n******\n')
-                            self.log.debug('padding top is: '+str(setting[0]))
-                            self.log.debug('padding right is:' +str(setting[1]))
-                            self.log.debug('padding bottom is: ' + str(setting[2]))
-                            self.log.debug('padding left is: ' +str(setting[3]))
+                            self.log.debug('padding top is: %s', setting[0])
+                            self.log.debug('padding right is: %s', setting[1])
+                            self.log.debug('padding bottom is: %s', setting[2])
+                            self.log.debug('padding left is: %s', setting[3])
 
                 # print "text-align is: "+str(text_align)
                 # print "\n***\nline is:\n     "+str(match.group(0))+'\n'
                 if debugabby:
                     # print "this line is a paragraph = "+str(is_paragraph)+", previous line was "+str(self.previous_was_paragraph)
-                    self.log.debug("styles for this line were:", styles)
-                    self.log.debug('newline is:')
-                    self.log.debug(blockquote_open_loop+blockquote_close_loop+
-                            paragraph_before+'<p style="'+text_indent+text_align+
-                            '">'+content+'</p>'+paragraph_after+'\n\n\n\n\n')
+                    self.log.debug("styles for this line were: %s", styles)
+                    self.log.debug('newline is: %s', blockquote_open_loop +
+                                   blockquote_close_loop +
+                                   paragraph_before +
+                                   '<p style="%s">%s</p>' %
+                                   (text_indent + text_align, content) +
+                                   paragraph_after +
+                                   '\n\n\n\n\n')
                 # print "is_paragraph is "+str(is_paragraph)+", previous_was_paragraph is "+str(self.previous_was_paragraph)
                 self.previous_was_paragraph = is_paragraph
                 # print "previous_was_paragraph is now set to "+str(self.previous_was_paragraph)+"\n\n\n"
@@ -731,10 +729,10 @@ class HeuristicProcessor(object):
         try:
             self.totalwords = self.get_word_count(html)
         except:
-            self.log.warn("Can't get wordcount")
+            self.log.warning("Can't get wordcount")
 
         if self.totalwords < 50:
-            self.log.warn("flow is too short, not running heuristics")
+            self.log.warning("flow is too short, not running heuristics")
             return html
 
         is_abbyy = self.is_abbyy(html)
@@ -801,12 +799,13 @@ class HeuristicProcessor(object):
         # more of the lines break in the same region of the document then unwrapping is required
         docanalysis = DocAnalysis(format, html)
         hardbreaks = docanalysis.line_histogram(.50)
-        self.log.debug("Hard line breaks check returned "+str(hardbreaks))
+        self.log.debug("Hard line breaks check returned %s", hardbreaks)
 
         # Calculate Length
         unwrap_factor = getattr(self.extra_opts, 'html_unwrap_factor', 0.4)
         length = docanalysis.line_length(unwrap_factor)
-        self.log.debug("Median line length is " + str(length) + ", calculated with " + format + " format")
+        self.log.debug("Median line length is %s, calculated with %s format",
+                       length, format)
 
         # ##### Unwrap lines ######
         if getattr(self.extra_opts, 'unwrap_lines', False):
@@ -827,8 +826,9 @@ class HeuristicProcessor(object):
 
         # If still no sections after unwrapping mark split points on lines with no punctuation
         if self.html_preprocess_sections < self.min_chapters and getattr(self.extra_opts, 'markup_chapter_headings', False):
-            self.log.debug("Looking for more split points based on punctuation,"
-                    " currently have " + str(self.html_preprocess_sections))
+            self.log.debug("Looking for more split points based on "
+                           "punctuation, currently have %s",
+                           self.html_preprocess_sections)
             chapdetect3 = re.compile(
                 r'<(?P<styles>(p|div)[^>]*)>\s*(?P<section>(<span[^>]*>)?\s*(?!([\W]+\s*)+)'
                 r'(<[ibu][^>]*>){0,2}\s*(<span[^>]*>)?\s*(<[ibu][^>]*>){0,2}\s*(<span[^>]*>)?\s*'
diff --git a/ebook_converter/ebooks/fb2/fb2ml.py b/ebook_converter/ebooks/fb2/fb2ml.py
index 696193b..9372c54 100644
--- a/ebook_converter/ebooks/fb2/fb2ml.py
+++ b/ebook_converter/ebooks/fb2/fb2ml.py
@@ -188,7 +188,7 @@ class FB2MLizer(object):
                 metadata['id'] = str(x).split(':')[-1]
                 break
         if metadata['id'] is None:
-            self.log.warn('No UUID identifier found')
+            self.log.warning('No UUID identifier found')
             metadata['id'] = str(uuid.uuid4())
 
         try:
@@ -311,7 +311,7 @@ class FB2MLizer(object):
             self.section_level += 1
 
         for item in self.oeb_book.spine:
-            self.log.debug('Converting %s to FictionBook2 XML' % item.href)
+            self.log.debug('Converting %s to FictionBook2 XML', item.href)
             stylizer = Stylizer(item.data, item.href, self.oeb_book, self.opts,
                                 self.opts.output_profile)
 
@@ -369,7 +369,7 @@ class FB2MLizer(object):
                                                  content_type, data))
                 except Exception as e:
                     self.log.error('Error: Could not include file %s because '
-                                   '%s.' % (item.href, e))
+                                   '%s.', item.href, e)
         return '\n'.join(images)
 
     def create_flat_toc(self, nodes, level):
@@ -528,7 +528,7 @@ class FB2MLizer(object):
                 fb2_out.append('<image l:href="#%s"/>' %
                                self.image_hrefs[ihref])
             else:
-                self.log.warn(u'Ignoring image not in manifest: %s' % ihref)
+                self.log.warning('Ignoring image not in manifest: %s', ihref)
         if tag in ('br', 'hr') or ems >= 1:
             if ems < 1:
                 multiplier = 1
diff --git a/ebook_converter/ebooks/htmlz/oeb2html.py b/ebook_converter/ebooks/htmlz/oeb2html.py
index 6affd63..6fc78ff 100644
--- a/ebook_converter/ebooks/htmlz/oeb2html.py
+++ b/ebook_converter/ebooks/htmlz/oeb2html.py
@@ -58,7 +58,7 @@ class OEB2HTML(object):
                   '<title>%s</title></head>'
                   '<body>' % entities.prepare_string_for_xml(self.book_title)]
         for item in oeb_book.spine:
-            self.log.debug('Converting %s to HTML...' % item.href)
+            self.log.debug('Converting %s to HTML...', item.href)
             self.rewrite_ids(item.data, item)
             base.rewrite_links(item.data, partial(self.rewrite_link,
                                                   page=item))
@@ -342,7 +342,7 @@ class OEB2HTMLClassCSSizer(OEB2HTML):
     def mlize_spine(self, oeb_book):
         output = []
         for item in oeb_book.spine:
-            self.log.debug('Converting %s to HTML...' % item.href)
+            self.log.debug('Converting %s to HTML...', item.href)
             self.rewrite_ids(item.data, item)
             base.rewrite_links(item.data, partial(self.rewrite_link,
                                                   page=item))
diff --git a/ebook_converter/ebooks/lrf/html/convert_from.py b/ebook_converter/ebooks/lrf/html/convert_from.py
index 813d8a1..73aa38e 100644
--- a/ebook_converter/ebooks/lrf/html/convert_from.py
+++ b/ebook_converter/ebooks/lrf/html/convert_from.py
@@ -331,9 +331,9 @@ class HTMLConverter(object):
                         if link['path'] == path:
                             self.links.remove(link)
                             break
-                    self.log.warn('Could not process '+path)
+                    self.log.warning('Could not process %s', path)
                     if self.verbose:
-                        self.log.exception(' ')
+                        self.log.exception(' ')  # WAT
             self.links = self.process_links()
             self.link_level += 1
             paths = [link['path'] for link in self.links]
@@ -400,7 +400,7 @@ class HTMLConverter(object):
                 with open(os.path.join(tdir,
                                        'html2lrf-verbose.html'), 'wb') as f:
                     f.write(str(soup).encode('utf-8'))
-                    self.log.info('Written preprocessed HTML to '+f.name)
+                    self.log.info('Written preprocessed HTML to %s', f.name)
             except Exception:
                 pass
 
@@ -416,8 +416,8 @@ class HTMLConverter(object):
                 self.css[selector] = self.override_css[selector]
 
         self.file_name = os.path.basename(path)
-        self.log.info('Processing %s' % (path if self.verbose else
-                                         self.file_name))
+        self.log.info('Processing %s', path if self.verbose else
+                      self.file_name)
 
         if not os.path.exists(path):
             # convertlit replaces & with %26 in file names
@@ -589,7 +589,7 @@ class HTMLConverter(object):
                 try:
                     index = self.book.pages().index(opage)
                 except ValueError:
-                    self.log.warning('%s is an empty file' % self.file_name)
+                    self.log.warning('%s is an empty file', self.file_name)
                     tb = self.book.create_text_block()
                     self.current_page.append(tb)
                     return tb
@@ -656,7 +656,7 @@ class HTMLConverter(object):
                hasattr(target.parent, 'objId'):
                 self.book.addTocEntry(ascii_text, tb)
             else:
-                self.log.debug("Cannot add link %s to TOC" % ascii_text)
+                self.log.debug("Cannot add link %s to TOC", ascii_text)
 
         def get_target_block(fragment, targets):
             '''Return the correct block for the <a name> element'''
@@ -1617,7 +1617,7 @@ class HTMLConverter(object):
                                                  tag[key]] = self.current_block
                                     self.current_block.must_append = True
                         else:
-                            self.log.debug('Could not follow link to ',
+                            self.log.debug('Could not follow link to %s',
                                            tag['href'])
                             self.process_children(tag, tag_css, tag_pseudo_css)
                 elif tag.has_attr('name') or tag.has_attr('id'):
@@ -1642,7 +1642,8 @@ class HTMLConverter(object):
                         self.process_image(path, tag_css, width, height,
                                            dropcaps=dropcaps, rescale=True)
                     elif not urllib.parse.urlparse(tag['src'])[0]:
-                        self.log.warn('Could not find image: '+tag['src'])
+                        self.log.warning('Could not find image: %s',
+                                         tag['src'])
                 else:
                     self.log.debug("Failed to process: %s", tag)
             elif tagname in ['style', 'link']:
@@ -1665,8 +1666,8 @@ class HTMLConverter(object):
                             self.page_break_found = True
                         ncss, npcss = self.parse_css(src)
                     except IOError:
-                        self.log.warn('Could not read stylesheet: %s',
-                                      tag['href'])
+                        self.log.warning('Could not read stylesheet: %s',
+                                         tag['href'])
                 if ncss:
                     update_css(ncss, self.css)
                     self.css.update(self.override_css)
@@ -1876,10 +1877,10 @@ class HTMLConverter(object):
                     self.process_table(tag, tag_css)
                 except Exception as err:
                     self.log.warning('An error occurred while processing a '
-                                     'table: %s. Ignoring table markup.' %
+                                     'table: %s. Ignoring table markup.',
                                      repr(err))
-                    self.log.exception('')
-                    self.log.debug('Bad table:\n%s' % str(tag)[:300])
+                    self.log.exception('')  # WAT
+                    self.log.debug('Bad table:\n%s', str(tag)[:300])
                     self.in_table = False
                     self.process_children(tag, tag_css, tag_pseudo_css)
                 finally:
@@ -1977,7 +1978,7 @@ def process_file(path, options, logger):
                 tpath = tf.name
             # PIL sometimes fails, for example on interlaced PNG files
             except IOError as err:
-                logger.warn('Could not read cover image: %s', err)
+                logger.warning('Could not read cover image: %s', err)
                 options.cover = None
         else:
             raise ConversionError('Cannot read from: %s', options.cover)
diff --git a/ebook_converter/ebooks/lrf/input.py b/ebook_converter/ebooks/lrf/input.py
index 731172e..11bfaf9 100644
--- a/ebook_converter/ebooks/lrf/input.py
+++ b/ebook_converter/ebooks/lrf/input.py
@@ -48,7 +48,8 @@ class Canvas(etree.XSLTExtension):
                 table.append(tr)
                 for obj, x, y in self.get_objects(canvas):
                     if obj.tag != 'TextBlock':
-                        self.log.warn(obj.tag, 'elements in Canvas not supported')
+                        self.log.warning('%s elements in Canvas not supported',
+                                         obj.tag)
                         continue
                     td = table.makeelement('td')
                     self.text_block.render_block(obj, td)
@@ -168,7 +169,7 @@ class TextBlock(etree.XSLTExtension):
         if deepest < 500:
             return
 
-        self.log.warn('Found deeply nested spans. Flattening.')
+        self.log.warning('Found deeply nested spans. Flattening.')
         # with open('/t/before.xml', 'wb') as f:
         #    f.write(etree.tostring(node, method='xml'))
 
@@ -270,7 +271,7 @@ class TextBlock(etree.XSLTExtension):
             self.add_text_to = (img, 'tail')
             self.add_text(child.tail)
         else:
-            self.log.warn('Unhandled Text element:', child.tag)
+            self.log.warning('Unhandled Text element: %s', child.tag)
 
 
 class Styles(etree.XSLTExtension):
diff --git a/ebook_converter/ebooks/odt/input.py b/ebook_converter/ebooks/odt/input.py
index ba22f63..602927f 100644
--- a/ebook_converter/ebooks/odt/input.py
+++ b/ebook_converter/ebooks/odt/input.py
@@ -24,7 +24,8 @@ class Extract(ODF2XHTML):
         if not os.path.exists('Pictures'):
             os.makedirs('Pictures')
         for name in zf.namelist():
-            if name.startswith('Pictures') and name not in {'Pictures', 'Pictures/'}:
+            if (name.startswith('Pictures') and
+                    name not in {'Pictures', 'Pictures/'}):
                 data = zf.read(name)
                 with open(name, 'wb') as f:
                     f.write(data)
@@ -46,13 +47,13 @@ class Extract(ODF2XHTML):
         self.extract_css(root, log)
         self.epubify_markup(root, log)
         self.apply_list_starts(root, log)
-        html = etree.tostring(root, encoding='utf-8',
-                xml_declaration=True)
+        html = etree.tostring(root, encoding='utf-8', xml_declaration=True)
         return html
 
     def extract_css(self, root, log):
         ans = []
-        for s in root.xpath('//*[local-name() = "style" and @type="text/css"]'):
+        for s in root.xpath('//*[local-name() = "style" and '
+                            '@type="text/css"]'):
             ans.append(s.text)
             s.getparent().remove(s)
 
@@ -63,11 +64,11 @@ class Extract(ODF2XHTML):
             if ns:
                 ns = '{%s}'%ns
             etree.SubElement(head, ns+'link', {'type':'text/css',
-                'rel':'stylesheet', 'href':'odfpy.css'})
+                                               'rel':'stylesheet',
+                                               'href':'odfpy.css'})
 
         css = u'\n\n'.join(ans)
-        parser = CSSParser(loglevel=logging.WARNING,
-                            log=_css_logger)
+        parser = CSSParser(loglevel=logging.WARNING, log=_css_logger)
         self.css = parser.parseString(css, validate=False)
 
         with open('odfpy.css', 'wb') as f:
@@ -209,7 +210,8 @@ class Extract(ODF2XHTML):
         for frm in self.document.topnode.getElementsByType(odFrame):
             try:
                 if frm.getAttrNS(odTEXTNS,u'anchor-type') == 'page':
-                    log.warn('Document has Pictures anchored to Page, will all end up before first page!')
+                    log.warning('Document has Pictures anchored to Page, will '
+                                'all end up before first page!')
                     break
             except ValueError:
                 pass
@@ -234,7 +236,8 @@ class Extract(ODF2XHTML):
                         # now it should be safe to remove the text:p
                         parent = para.parentNode
                         parent.removeChild(para)
-                        log("Removed cover image paragraph from document...")
+                        log.info("Removed cover image paragraph from "
+                                 "document...")
                         break
 
     def filter_load(self, odffile, mi, log):
@@ -267,7 +270,7 @@ class Extract(ODF2XHTML):
         if not os.path.exists(odir):
             os.makedirs(odir)
         with directory.CurrentDir(odir):
-            log('Extracting ODT file...')
+            log.info('Extracting ODT file...')
             stream.seek(0)
             mi = get_metadata(stream, 'odt')
             if not mi.title:
diff --git a/ebook_converter/ebooks/oeb/base.py b/ebook_converter/ebooks/oeb/base.py
index 505e131..a3fc470 100644
--- a/ebook_converter/ebooks/oeb/base.py
+++ b/ebook_converter/ebooks/oeb/base.py
@@ -904,7 +904,7 @@ class Manifest(object):
         def _parse_xhtml(self, data):
             orig_data = data
             fname = urllib.parse.unquote(self.href)
-            self.oeb.log.debug('Parsing', fname, '...')
+            self.oeb.log.debug('Parsing %s ...', fname)
             self.oeb.html_preprocessor.current_href = self.href
             try:
                 data = parse_utils.parse_html(data, log=self.oeb.log,
@@ -924,7 +924,7 @@ class Manifest(object):
             if has_html in data:
                 return self._parse_xhtml(data)
 
-            self.oeb.log.debug('Converting', self.href, '...')
+            self.oeb.log.debug('Converting %s ...', self.href)
 
             from ebook_converter.ebooks.txt.processor import convert_markdown
 
@@ -941,7 +941,7 @@ class Manifest(object):
             from css_parser.css import CSSRule
             log.setLevel(logging.WARN)
             log.raiseExceptions = False
-            self.oeb.log.debug('Parsing', self.href, '...')
+            self.oeb.log.debug('Parsing %s ...', self.href)
             data = self.oeb.decode(data)
             data = self.oeb.css_preprocessor(data, add_namespace=False)
             parser = CSSParser(loglevel=logging.WARNING,
@@ -957,11 +957,11 @@ class Manifest(object):
         def _fetch_css(self, path):
             hrefs = self.oeb.manifest.hrefs
             if path not in hrefs:
-                self.oeb.logger.warn('CSS import of missing file %r' % path)
+                self.oeb.logger.warning('CSS import of missing file %s', path)
                 return (None, None)
             item = hrefs[path]
             if item.media_type not in OEB_STYLES:
-                self.oeb.logger.warn('CSS import of non-CSS file %r' % path)
+                self.oeb.logger.warning('CSS import of non-CSS file %s', path)
                 return (None, None)
             data = item.data.cssText
             enc = None if isinstance(data, str) else 'utf-8'
@@ -1002,8 +1002,8 @@ class Manifest(object):
             elif mt in OEB_STYLES:
                 data = self._parse_css(data)
             elif mt == 'text/plain':
-                self.oeb.log.warn('%s contains data in TXT format' % self.href,
-                                  'converting to HTML')
+                self.oeb.log.warning('%s contains data in TXT format. '
+                                     'Converting to HTML', self.href)
                 data = self._parse_txt(data)
                 self.media_type = XHTML_MIME
             self._data = data
diff --git a/ebook_converter/ebooks/oeb/parse_utils.py b/ebook_converter/ebooks/oeb/parse_utils.py
index 3d0a119..50d8b95 100644
--- a/ebook_converter/ebooks/oeb/parse_utils.py
+++ b/ebook_converter/ebooks/oeb/parse_utils.py
@@ -65,7 +65,7 @@ def merge_multiple_html_heads_and_bodies(root, log=None):
             body.append(x)
     tuple(map(root.append, (head, body)))
     if log is not None:
-        log.warn('Merging multiple <head> and <body> sections')
+        log.warning('Merging multiple <head> and <body> sections')
     return root
 
 
@@ -122,7 +122,7 @@ def clean_word_doc(data, log):
     for match in re.finditer(r'xmlns:(\S+?)=".*?microsoft.*?"', data):
         prefixes.append(match.group(1))
     if prefixes:
-        log.warn('Found microsoft markup, cleaning...')
+        log.warning('Found microsoft markup, cleaning...')
         # Remove empty tags as they are not rendered by browsers
         # but can become renderable HTML tags like <p/> if the
         # document is parsed by an HTML parser
@@ -214,13 +214,13 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
             data = etree.fromstring(data)
             check_for_html5(pre, data)
         except (HTML5Doc, etree.XMLSyntaxError):
-            log.debug('Parsing %s as HTML' % filename)
+            log.debug('Parsing %s as HTML', filename)
             data = raw
             try:
                 data = html5_parse(data)
             except Exception:
-                log.exception(
-                    'HTML 5 parsing failed, falling back to older parsers')
+                log.exception('HTML 5 parsing failed, falling back to older '
+                              'parsers')
                 data = _html4_parse(data)
 
     if has_html4_doctype or data.tag == 'HTML' or (len(data) and (data[-1].get('LANG') or data[-1].get('DIR'))):
@@ -239,7 +239,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
     if barename(data.tag) != 'html':
         if barename(data.tag) in non_html_file_tags:
             raise NotHTML(data.tag)
-        log.warn('File %r does not appear to be (X)HTML'%filename)
+        log.warning('File %s does not appear to be (X)HTML', filename)
         nroot = etree.fromstring('<html></html>')
         has_body = False
         for child in list(data):
@@ -248,7 +248,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
                 break
         parent = nroot
         if not has_body:
-            log.warn('File %r appears to be a HTML fragment'%filename)
+            log.warning('File %s appears to be a HTML fragment', filename)
             nroot = etree.fromstring('<html><body/></html>')
             parent = nroot[0]
         for child in list(data.iter()):
@@ -260,7 +260,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
 
     # Force into the XHTML namespace
     if not namespace(data.tag):
-        log.warn('Forcing', filename, 'into XHTML namespace')
+        log.warning('Forcing %s into XHTML namespace', filename)
         data.attrib['xmlns'] = const.XHTML_NS
         data = etree.tostring(data, encoding='unicode')
 
@@ -272,10 +272,8 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
             try:
                 data = etree.fromstring(data)
             except etree.XMLSyntaxError:
-                log.warn('Stripping comments from %s'%
-                        filename)
-                data = re.compile(r'<!--.*?-->', re.DOTALL).sub('',
-                        data)
+                log.warning('Stripping comments from %s', filename)
+                data = re.compile(r'<!--.*?-->', re.DOTALL).sub('', data)
                 data = data.replace(
                     "<?xml version='1.0' encoding='utf-8'?><o:p></o:p>",
                     '')
@@ -283,7 +281,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
                 try:
                     data = etree.fromstring(data)
                 except etree.XMLSyntaxError:
-                    log.warn('Stripping meta tags from %s'% filename)
+                    log.warning('Stripping meta tags from %s', filename)
                     data = re.sub(r'<meta\s+[^>]+?>', '', data)
                     data = etree.fromstring(data)
     elif namespace(data.tag) != const.XHTML_NS:
@@ -308,7 +306,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
     head = xpath(data, '/h:html/h:head')
     head = head[0] if head else None
     if head is None:
-        log.warn('File %s missing <head/> element' % filename)
+        log.warning('File %s missing <head/> element', filename)
         head = etree.Element(XHTML('head'))
         data.insert(0, head)
         title = etree.SubElement(head, XHTML('title'))
@@ -335,7 +333,7 @@ def parse_html(data, log=None, decoder=None, preprocessor=None,
             body.getparent().remove(body)
             data.append(body)
         else:
-            log.warn('File %s missing <body/> element' % filename)
+            log.warning('File %s missing <body/> element', filename)
             etree.SubElement(data, XHTML('body'))
 
     # Remove microsoft office markup
diff --git a/ebook_converter/ebooks/oeb/polish/container.py b/ebook_converter/ebooks/oeb/polish/container.py
index 8ee048a..928325a 100644
--- a/ebook_converter/ebooks/oeb/polish/container.py
+++ b/ebook_converter/ebooks/oeb/polish/container.py
@@ -1141,8 +1141,8 @@ class EpubContainer(Container):
                     zf = ZipFile(stream)
                     zf.extractall(tdir)
                 except:
-                    log.exception('EPUB appears to be invalid ZIP file, trying a'
-                            ' more forgiving ZIP parser')
+                    log.exception('EPUB appears to be invalid ZIP file, '
+                                  'trying a more forgiving ZIP parser')
                     from ebook_converter.utils.localunzip import extractall
                     stream.seek(0)
                     extractall(stream, path=tdir)
@@ -1481,7 +1481,7 @@ class AZW3Container(Container):
             'ebook_converter.ebooks.oeb.polish.container', 'do_explode',
             args=(pathtoazw3, tdir), no_output=True)['result']
         except WorkerError as e:
-            log(e.orig_tb)
+            log.error(e.orig_tb)
             raise InvalidMobi('Failed to explode MOBI')
         super(AZW3Container, self).__init__(tdir, opf_path, log)
         self.obfuscated_fonts = {x.replace(os.sep, '/') for x in obfuscated_fonts}
diff --git a/ebook_converter/ebooks/oeb/reader.py b/ebook_converter/ebooks/oeb/reader.py
index 5cbf259..9f19704 100644
--- a/ebook_converter/ebooks/oeb/reader.py
+++ b/ebook_converter/ebooks/oeb/reader.py
@@ -111,14 +111,14 @@ class OEBReader(object):
                                                  encoding=None)
             try:
                 opf = etree.fromstring(data)
-                self.logger.warn('OPF contains invalid HTML named entities')
+                self.logger.warning('OPF contains invalid HTML named entities')
             except etree.XMLSyntaxError:
                 data = re.sub(r'(?is)<tours>.+</tours>', '', data)
                 data = data.replace('<dc-metadata>',
                                     '<dc-metadata xmlns:dc="'
                                     'http://purl.org/metadata/dublin_core">')
                 opf = etree.fromstring(data)
-                self.logger.warn('OPF contains invalid tours section')
+                self.logger.warning('OPF contains invalid tours section')
 
         ns = parse_utils.namespace(opf.tag)
         if ns not in ('', const.OPF1_NS, const.OPF2_NS):
@@ -172,7 +172,7 @@ class OEBReader(object):
                 except KeyboardInterrupt:
                     raise
                 except Exception:
-                    self.logger.exception('Failed to parse content in %s' %
+                    self.logger.exception('Failed to parse content in %s',
                                           item.href)
                     bad.append(item)
                     self.oeb.manifest.remove(item)
@@ -195,7 +195,7 @@ class OEBReader(object):
                         data = item.data
                     except Exception:
                         self.oeb.log.exception('Failed to read from manifest '
-                                               'entry with id: %s, ignoring' %
+                                               'entry with id: %s, ignoring',
                                                item.id)
                         invalid.add(item)
                         continue
@@ -216,7 +216,7 @@ class OEBReader(object):
                             scheme = urllib.parse.urlparse(href).scheme
                         except Exception:
                             self.oeb.log.exception('Skipping invalid href: '
-                                                   '%r' % href)
+                                                   '%s', href)
                             continue
                         if not scheme and href not in known:
                             new.add(href)
@@ -244,12 +244,13 @@ class OEBReader(object):
                     continue
                 if not self.oeb.container.exists(href):
                     if href not in warned:
-                        self.logger.warn('Referenced file %r not found' % href)
+                        self.logger.warning('Referenced file %s not found',
+                                            href)
                         warned.add(href)
                     continue
                 if href not in warned:
-                    self.logger.warn('Referenced file %r not in manifest' %
-                                     href)
+                    self.logger.warning('Referenced file %s not in manifest',
+                                        href)
                     warned.add(href)
                 id, _ = manifest.generate(id='added')
                 guessed = mimetypes.guess_type(href)[0]
@@ -275,13 +276,13 @@ class OEBReader(object):
                 media_type = media_type.lower()
             fallback = elem.get('fallback')
             if href in manifest.hrefs:
-                self.logger.warn('Duplicate manifest entry for %r' % href)
+                self.logger.warning('Duplicate manifest entry for %s', href)
                 continue
             if not self.oeb.container.exists(href):
-                self.logger.warn('Manifest item %r not found' % href)
+                self.logger.warning('Manifest item %s not found', href)
                 continue
             if id in manifest.ids:
-                self.logger.warn('Duplicate manifest id %r' % id)
+                self.logger.warning('Duplicate manifest id %s', id)
                 id, href = manifest.generate(id, href)
             manifest.add(id, href, media_type, fallback)
         invalid = self._manifest_prune_invalid()
@@ -323,8 +324,8 @@ class OEBReader(object):
             if item.href in removed_items_to_ignore:
                 continue
             if version >= 2:
-                self.logger.warn(
-                    'Spine-referenced file %r not in spine' % item.href)
+                self.logger.warning('Spine-referenced file %s not in spine',
+                                    item.href)
             spine.add(item, linear=False)
 
     def _spine_from_opf(self, opf):
@@ -333,7 +334,7 @@ class OEBReader(object):
         for elem in base.xpath(opf, '/o2:package/o2:spine/o2:itemref'):
             idref = elem.get('idref')
             if idref not in manifest.ids:
-                self.logger.warn('Spine item %r not found' % idref)
+                self.logger.warning('Spine item %s not found', idref)
                 continue
             item = manifest.ids[idref]
             if (item.media_type.lower() in base.OEB_DOCS and
@@ -346,8 +347,8 @@ class OEBReader(object):
                     item.media_type = base.XHTML_MIME
                     spine.add(item, elem.get('linear'))
                 else:
-                    self.oeb.log.warn('The item %s is not a XML document.'
-                                      ' Removing it from spine.' % item.href)
+                    self.oeb.log.warning('The item %s is not a XML document.'
+                                         ' Removing it from spine.', item.href)
         if len(spine) == 0:
             raise base.OEBError("Spine is empty")
         self._spine_add_extra()
@@ -369,7 +370,8 @@ class OEBReader(object):
                         corrected_href = href
                         break
                 if corrected_href is None:
-                    self.logger.warn('Guide reference %r not found' % ref_href)
+                    self.logger.warning('Guide reference %s not found',
+                                        ref_href)
                     continue
                 ref_href = corrected_href
             typ = elem.get('type')
@@ -411,7 +413,7 @@ class OEBReader(object):
             if path and path not in self.oeb.manifest.hrefs:
                 path = base.urlnormalize(path)
             if href and path not in self.oeb.manifest.hrefs:
-                self.logger.warn('TOC reference %r not found' % href)
+                self.logger.warning('TOC reference %s not found', href)
                 gc = base.xpath(child, 'ncx:navPoint')
                 if not gc:
                     # This node is useless
@@ -488,7 +490,7 @@ class OEBReader(object):
                 continue
             path, _ = urllib.parse.urldefrag(base.urlnormalize(href))
             if path not in self.oeb.manifest.hrefs:
-                self.logger.warn('TOC reference %r not found' % href)
+                self.logger.warning('TOC reference %s not found', href)
                 continue
             id = site.get('id')
             toc.add(title, href, id=id)
@@ -528,7 +530,7 @@ class OEBReader(object):
         return True
 
     def _toc_from_spine(self, opf):
-        self.log.warn('Generating default TOC from spine...')
+        self.log.warning('Generating default TOC from spine...')
         toc = self.oeb.toc
         titles = []
         headers = []
@@ -656,7 +658,7 @@ class OEBReader(object):
             if item is not None and item.media_type in base.OEB_IMAGES:
                 return item
             else:
-                self.logger.warn('Invalid cover image @id %r' % id)
+                self.logger.warning('Invalid cover image @id %s', id)
         hcover = self.oeb.spine[0]
         if 'cover' in self.oeb.guide:
             href = self.oeb.guide['cover'].href
@@ -705,8 +707,8 @@ class OEBReader(object):
             items = [x for x in self.oeb.manifest if x.href == href]
             for x in items:
                 if x not in self.oeb.spine:
-                    self.oeb.log.warn('Removing duplicate manifest item with '
-                                      'id:', x.id)
+                    self.oeb.log.warning('Removing duplicate manifest item '
+                                         'with id: %s', x.id)
                     self.oeb.manifest.remove_duplicate_item(x)
 
     def _all_from_opf(self, opf):
diff --git a/ebook_converter/ebooks/oeb/stylizer.py b/ebook_converter/ebooks/oeb/stylizer.py
index c3389df..ab06fea 100644
--- a/ebook_converter/ebooks/oeb/stylizer.py
+++ b/ebook_converter/ebooks/oeb/stylizer.py
@@ -241,11 +241,14 @@ class Stylizer(object):
                                 continue
                             hrefs = self.oeb.manifest.hrefs
                             if ihref not in hrefs:
-                                self.logger.warn('Ignoring missing stylesheet in @import rule:', rule.href)
+                                self.logger.warning('Ignoring missing '
+                                                    'stylesheet in @import '
+                                                    'rule: %s', rule.href)
                                 continue
                             sitem = hrefs[ihref]
                             if sitem.media_type not in base.OEB_STYLES:
-                                self.logger.warn('CSS @import of non-CSS file %r' % rule.href)
+                                self.logger.warning('CSS @import of non-CSS '
+                                                    'file %s', rule.href)
                                 continue
                             stylesheets.append(sitem.data)
                     # Make links to resources absolute, since these rules will
@@ -261,14 +264,12 @@ class Stylizer(object):
                 path = item.abshref(href)
                 sitem = oeb.manifest.hrefs.get(path, None)
                 if sitem is None:
-                    self.logger.warn(
-                        'Stylesheet %r referenced by file %r not in manifest' %
-                        (path, item.href))
+                    self.logger.warning('Stylesheet %s referenced by file %s '
+                                        'not in manifest', path, item.href)
                     continue
                 if not hasattr(sitem.data, 'cssRules'):
-                    self.logger.warn(
-                    'Stylesheet %r referenced by file %r is not CSS'%(path,
-                        item.href))
+                    self.logger.warning('Stylesheet %s referenced by file %s '
+                                        'is not CSS', path, item.href)
                     continue
                 stylesheets.append(sitem.data)
         csses = {'extra_css':extra_css, 'user_css':user_css}
@@ -280,9 +281,8 @@ class Stylizer(object):
                             validate=False)
                     stylesheets.append(stylesheet)
                 except Exception:
-                    self.logger.exception('Failed to parse %s, ignoring.'%w)
-                    self.logger.debug('Bad css: ')
-                    self.logger.debug(x)
+                    self.logger.exception('Failed to parse %s, ignoring.', w)
+                    self.logger.debug('Bad css: %s', x)
 
         # using oeb to store the rules, page rule and font face rules
         # and generating them again if opts, profile or stylesheets are different
@@ -303,7 +303,8 @@ class Stylizer(object):
             try:
                 matches = tuple(select(text))
             except SelectorError as err:
-                self.logger.error('Ignoring CSS rule with invalid selector: %r (%s)' % (text, err))
+                self.logger.error('Ignoring CSS rule with invalid selector: '
+                                  '%s (%s)', text, err)
                 continue
 
             if fl is not None:
@@ -367,11 +368,11 @@ class Stylizer(object):
     def _fetch_css_file(self, path):
         hrefs = self.oeb.manifest.hrefs
         if path not in hrefs:
-            self.logger.warn('CSS import of missing file %r' % path)
+            self.logger.warning('CSS import of missing file %s', path)
             return (None, None)
         item = hrefs[path]
         if item.media_type not in base.OEB_STYLES:
-            self.logger.warn('CSS import of non-CSS file %r' % path)
+            self.logger.warning('CSS import of non-CSS file %r', path)
             return (None, None)
         data = item.data.cssText
         if not isinstance(data, bytes):
diff --git a/ebook_converter/ebooks/oeb/transforms/data_url.py b/ebook_converter/ebooks/oeb/transforms/data_url.py
index 166ae45..13bfd81 100644
--- a/ebook_converter/ebooks/oeb/transforms/data_url.py
+++ b/ebook_converter/ebooks/oeb/transforms/data_url.py
@@ -36,16 +36,16 @@ class DataURL(object):
                 data = polyglot.as_bytes(data)
                 fmt = what(None, data)
                 if not fmt:
-                    self.log.warn('Image encoded as data URL has unknown '
-                                  'format, ignoring')
+                    self.log.warning('Image encoded as data URL has unknown '
+                                     'format, ignoring')
                     continue
                 img.set('src',
                         item.relhref(self.convert_image_data_uri(data, fmt,
                                                                  oeb)))
 
     def convert_image_data_uri(self, data, fmt, oeb):
-        self.log('Found image encoded as data URI converting it to normal '
-                 'image')
+        self.log.info('Found image encoded as data URI converting it to '
+                      'normal image')
         item_id, item_href = oeb.manifest.generate('data-url-image',
                                                    'data-url-image.' + fmt)
         oeb.manifest.add(item_id, item_href,
diff --git a/ebook_converter/ebooks/oeb/transforms/filenames.py b/ebook_converter/ebooks/oeb/transforms/filenames.py
index 4b975ee..1e72735 100644
--- a/ebook_converter/ebooks/oeb/transforms/filenames.py
+++ b/ebook_converter/ebooks/oeb/transforms/filenames.py
@@ -117,8 +117,9 @@ class UniqueFilenames(object):  # {{{
                 self.seen_filenames.add(fname)
 
         if self.rename_map:
-            self.log('Found non-unique filenames, renaming to support broken'
-                    ' EPUB readers like FBReader, Aldiko and Stanza...')
+            self.log.info('Found non-unique filenames, renaming to support '
+                          'broken EPUB readers like FBReader, Aldiko and '
+                          'Stanza...')
             from pprint import pformat
             self.log.debug(pformat(self.rename_map))
 
@@ -173,8 +174,8 @@ class FlatFilenames(object):  # {{{
                 oeb.spine.insert(isp, nitem, item.linear)
 
         if self.rename_map:
-            self.log('Found non-flat filenames, renaming to support broken'
-                    ' EPUB readers like FBReader...')
+            self.log.info('Found non-flat filenames, renaming to support '
+                          'broken EPUB readers like FBReader...')
             from pprint import pformat
             self.log.debug(pformat(self.rename_map))
             self.log.debug(pformat(self.renamed_items_map))
diff --git a/ebook_converter/ebooks/oeb/transforms/flatcss.py b/ebook_converter/ebooks/oeb/transforms/flatcss.py
index c336bc4..5492ae3 100644
--- a/ebook_converter/ebooks/oeb/transforms/flatcss.py
+++ b/ebook_converter/ebooks/oeb/transforms/flatcss.py
@@ -182,8 +182,8 @@ class CSSFlattener(object):
             else:
                 from ebook_converter.ebooks.oeb.normalize_css import normalize_filter_css
                 self.filter_css = frozenset(normalize_filter_css(self.filter_css))
-                self.oeb.log.debug('Filtering CSS properties: %s'%
-                    ', '.join(self.filter_css))
+                self.oeb.log.debug('Filtering CSS properties: %s',
+                                   ', '.join(self.filter_css))
 
         for item in oeb.manifest.values():
             # Make all links to resources absolute, as these sheets will be
@@ -231,13 +231,13 @@ class CSSFlattener(object):
             msg = ('No embeddable fonts found for family: %r'%family)
             if failure_critical:
                 raise ValueError(msg)
-            self.oeb.log.warn(msg)
+            self.oeb.log.warning(msg)
             return body_font_family, efi
         if not faces:
             msg = ('No embeddable fonts found for family: %r'%family)
             if failure_critical:
                 raise ValueError(msg)
-            self.oeb.log.warn(msg)
+            self.oeb.log.warning(msg)
             return body_font_family, efi
 
         for i, font in enumerate(faces):
@@ -258,7 +258,7 @@ class CSSFlattener(object):
             if i == 0:
                 generic_family = panose_to_css_generic_family(font['panose'])
                 body_font_family = "'%s',%s"%(font['font-family'], generic_family)
-                self.oeb.log('Embedding font: %s'%font['font-family'])
+                self.oeb.log.info('Embedding font: %s', font['font-family'])
             for k in ('font-weight', 'font-style', 'font-stretch'):
                 if font[k] != 'normal':
                     cfont[k] = font[k]
@@ -323,8 +323,7 @@ class CSSFlattener(object):
             sbase = max(list(sizes.items()), key=operator.itemgetter(1))[0]
         except:
             sbase = 12.0
-        self.oeb.logger.info(
-            "Source base font size is %0.05fpt" % sbase)
+        self.oeb.logger.info("Source base font size is %0.05fpt", sbase)
         return sbase
 
     def clean_edges(self, cssdict, style, fsize):
@@ -346,8 +345,7 @@ class CSSFlattener(object):
                     try:
                         value = round(value / slineh) * dlineh
                     except:
-                        self.oeb.logger.warning(
-                                'Invalid length:', value)
+                        self.oeb.logger.warning('Invalid length: %s', value)
                         value = 0.0
                     cssdict[property] = "%0.5fem" % (value / fsize)
 
diff --git a/ebook_converter/ebooks/oeb/transforms/guide.py b/ebook_converter/ebooks/oeb/transforms/guide.py
index ffe6feb..f02783a 100644
--- a/ebook_converter/ebooks/oeb/transforms/guide.py
+++ b/ebook_converter/ebooks/oeb/transforms/guide.py
@@ -1,8 +1,3 @@
-__license__ = 'GPL v3'
-__copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
 class Clean(object):
     '''Clean up guide, leaving only known values '''
 
@@ -28,7 +23,8 @@ class Clean(object):
             if covers:
                 ref = covers[0][0]
                 if len(covers) > 1:
-                    self.log('Choosing %s:%s as the cover'%(ref.type, ref.href))
+                    self.log.info('Choosing %s:%s as the cover', ref.type,
+                                  ref.href)
                 ref.type = 'cover'
                 self.oeb.guide.refs['cover'] = ref
 
diff --git a/ebook_converter/ebooks/oeb/transforms/jacket.py b/ebook_converter/ebooks/oeb/transforms/jacket.py
index 1afd078..4231809 100644
--- a/ebook_converter/ebooks/oeb/transforms/jacket.py
+++ b/ebook_converter/ebooks/oeb/transforms/jacket.py
@@ -34,19 +34,19 @@ class RemoveFirstImage:
                 continue
             removed = self.remove_images(item)
             if removed > 0:
-                self.log('Removed first image')
+                self.log.info('Removed first image')
                 body = XPath('//h:body')(item.data)
                 if body:
                     raw = xml2text(body[0]).strip()
                     imgs = XPath('//h:img|//svg:svg')(item.data)
                     if not raw and not imgs:
-                        self.log('Removing %s as it has no content' %
-                                 item.href)
+                        self.log.info('Removing %s as it has no content',
+                                      item.href)
                         self.oeb.manifest.remove(item)
                         deleted_item = item
                 break
         else:
-            self.log.warn('Could not find first image to remove')
+            self.log.warning('Could not find first image to remove')
         if deleted_item is not None:
             for item in list(self.oeb.toc):
                 href = urllib.parse.urldefrag(item.href)[0]
diff --git a/ebook_converter/ebooks/oeb/transforms/metadata.py b/ebook_converter/ebooks/oeb/transforms/metadata.py
index 2198276..a5e391d 100644
--- a/ebook_converter/ebooks/oeb/transforms/metadata.py
+++ b/ebook_converter/ebooks/oeb/transforms/metadata.py
@@ -101,7 +101,7 @@ class MergeMetadata(object):
         _oim = override_input_metadata
         self.oeb, self.log = oeb, oeb.log
         m = self.oeb.metadata
-        self.log('Merging user specified metadata...')
+        self.log.info('Merging user specified metadata...')
         meta_info_to_oeb_metadata(mi, m, oeb.log,
                                   override_input_metadata=_oim)
         cover_id = self.set_cover(mi, opts.prefer_metadata_cover)
@@ -210,8 +210,8 @@ class MergeMetadata(object):
                 text = ''
             text = re.sub(r'\s+', '', text)
             if not text and not XPath('//h:img|//svg:svg')(item.data):
-                self.log('Removing %s as it is a wrapper around the cover '
-                         'image' % item.href)
+                self.log.info('Removing %s as it is a wrapper around the '
+                              'cover image', item.href)
                 self.oeb.spine.remove(item)
                 self.oeb.manifest.remove(item)
                 self.oeb.guide.remove_by_href(item.href)
diff --git a/ebook_converter/ebooks/oeb/transforms/page_margin.py b/ebook_converter/ebooks/oeb/transforms/page_margin.py
index bfd81c3..634cae0 100644
--- a/ebook_converter/ebooks/oeb/transforms/page_margin.py
+++ b/ebook_converter/ebooks/oeb/transforms/page_margin.py
@@ -5,11 +5,6 @@ from ebook_converter.ebooks.oeb import parse_utils
 from ebook_converter.ebooks.oeb.base import XPath
 
 
-__license__ = 'GPL v3'
-__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
 class RemoveAdobeMargins(object):
     '''
     Remove margins specified in Adobe's page templates.
@@ -19,12 +14,13 @@ class RemoveAdobeMargins(object):
         self.oeb, self.opts, self.log = oeb, opts, log
 
         for item in self.oeb.manifest:
-            if item.media_type in {
-                'application/vnd.adobe-page-template+xml', 'application/vnd.adobe.page-template+xml',
-                'application/adobe-page-template+xml', 'application/adobe.page-template+xml',
-            } and hasattr(item.data, 'xpath'):
-                self.log('Removing page margins specified in the'
-                        ' Adobe page template')
+            if (item.media_type in {'application/vnd.adobe-page-template+xml',
+                                    'application/vnd.adobe.page-template+xml',
+                                    'application/adobe-page-template+xml',
+                                    'application/adobe.page-template+xml'} and
+                    hasattr(item.data, 'xpath')):
+                self.log.info('Removing page margins specified in the '
+                              'Adobe page template')
                 for elem in item.data.xpath(
                         '//*[@margin-bottom or @margin-top '
                         'or @margin-left or @margin-right]'):
@@ -59,7 +55,7 @@ class RemoveFakeMargins(object):
         if stylesheet is None:
             return
 
-        self.log('Removing fake margins...')
+        self.log.info('Removing fake margins...')
 
         stylesheet = stylesheet.data
 
@@ -73,8 +69,8 @@ class RemoveFakeMargins(object):
             try:
                 self.process_level(level)
             except NegativeTextIndent:
-                self.log.debug('Negative text indent detected at level '
-                        ' %s, ignoring this level'%level)
+                self.log.debug('Negative text indent detected at level %s, '
+                               'ignoring this level', level)
 
     def get_margins(self, elem):
         cls = elem.get('class', None)
@@ -102,19 +98,21 @@ class RemoveFakeMargins(object):
             self.stats[level+'_left'][lm] += 1
             self.stats[level+'_right'][rm] += 1
 
-        self.log.debug(level, ' left margin stats:', self.stats[level+'_left'])
-        self.log.debug(level, ' right margin stats:', self.stats[level+'_right'])
+        self.log.debug('%s left margin stats: %s', level,
+                       self.stats[level+'_left'])
+        self.log.debug('%s right margin stats: %s', level,
+                       self.stats[level+'_right'])
 
         remove_left = self.analyze_stats(self.stats[level+'_left'])
         remove_right = self.analyze_stats(self.stats[level+'_right'])
 
         if remove_left:
             mcl = self.stats[level+'_left'].most_common(1)[0][0]
-            self.log('Removing level %s left margin of:'%level, mcl)
+            self.log.info('Removing level %s left margin of: %s', level, mcl)
 
         if remove_right:
             mcr = self.stats[level+'_right'].most_common(1)[0][0]
-            self.log('Removing level %s right margin of:'%level, mcr)
+            self.log.info('Removing level %s right margin of: %s', level, mcr)
 
         if remove_left or remove_right:
             for elem in elems:
@@ -151,7 +149,7 @@ class RemoveFakeMargins(object):
         remove = set()
         for k, v in self.levels.items():
             num = len(v)
-            self.log.debug('Found %d items of level:'%num, k)
+            self.log.debug('Found %s items of level: %s', num, k)
             level = int(k.split('_')[-1])
             tag = k.split('_')[0]
             if tag == 'p' and num < 25:
@@ -169,7 +167,7 @@ class RemoveFakeMargins(object):
 
         for k in remove:
             self.levels.pop(k)
-            self.log.debug('Ignoring level', k)
+            self.log.debug('Ignoring level %s', k)
 
     def analyze_stats(self, stats):
         if not stats:
diff --git a/ebook_converter/ebooks/oeb/transforms/rescale.py b/ebook_converter/ebooks/oeb/transforms/rescale.py
index d1677be..fa81478 100644
--- a/ebook_converter/ebooks/oeb/transforms/rescale.py
+++ b/ebook_converter/ebooks/oeb/transforms/rescale.py
@@ -45,12 +45,14 @@ class RescaleImages(object):
 
                 try:
                     if self.check_colorspaces and img.mode == 'CMYK':
-                        self.log.warn(
-                            'The image %s is in the CMYK colorspace, converting it '
-                            'to RGB as Adobe Digital Editions cannot display CMYK' % item.href)
+                        self.log.warning('The image %s is in the CMYK '
+                                         'colorspace, converting it to RGB as '
+                                         'Adobe Digital Editions cannot '
+                                         'display CMYK', item.href)
                         img = img.convert('RGB')
                 except Exception:
-                    self.log.exception('Failed to convert image %s from CMYK to RGB' % item.href)
+                    self.log.exception('Failed to convert image %s from CMYK '
+                                       'to RGB', item.href)
 
                 scaled, new_width, new_height = uimg.fit_image(width, height,
                                                                page_width,
@@ -58,18 +60,20 @@ class RescaleImages(object):
                 if scaled:
                     new_width = max(1, new_width)
                     new_height = max(1, new_height)
-                    self.log('Rescaling image from %dx%d to %dx%d'%(
-                        width, height, new_width, new_height), item.href)
+                    self.log('Rescaling image from %sx%s to %sx%s %s', width,
+                             height, new_width, new_height, item.href)
                     try:
                         img = img.resize((new_width, new_height))
                     except Exception:
-                        self.log.exception('Failed to rescale image: %s' % item.href)
+                        self.log.exception('Failed to rescale image: %s',
+                                           item.href)
                         continue
                     buf = BytesIO()
                     try:
                         img.save(buf, ext)
                     except Exception:
-                        self.log.exception('Failed to rescale image: %s' % item.href)
+                        self.log.exception('Failed to rescale image: %s',
+                                           item.href)
                     else:
                         item.data = buf.getvalue()
                         item.unload_data_from_memory()
diff --git a/ebook_converter/ebooks/oeb/transforms/split.py b/ebook_converter/ebooks/oeb/transforms/split.py
index 0aeeb0b..77e26ca 100644
--- a/ebook_converter/ebooks/oeb/transforms/split.py
+++ b/ebook_converter/ebooks/oeb/transforms/split.py
@@ -59,7 +59,8 @@ class Split(object):
     def __call__(self, oeb, opts):
         self.oeb = oeb
         self.log = oeb.log
-        self.log('Splitting markup on page breaks and flow limits, if any...')
+        self.log.info('Splitting markup on page breaks and flow limits, if '
+                      'any...')
         self.opts = opts
         self.map = {}
         for item in list(self.oeb.manifest.items):
@@ -127,8 +128,7 @@ class Split(object):
                         page_breaks.add(elem)
             except SelectorError as err:
                 self.log.warn('Ignoring page breaks specified with invalid '
-                              'CSS selector: %r (%s)' %
-                              (selector, err))
+                              'CSS selector: %s (%s)', selector, err)
 
         for i, elem in enumerate(item.data.iter('*')):
             try:
@@ -221,13 +221,13 @@ class FlowSplitter(object):
 
         if self.max_flow_size > 0:
             lt_found = False
-            self.log('\tLooking for large trees in %s...' % item.href)
+            self.log.info('\tLooking for large trees in %s...', item.href)
             trees = list(self.trees)
             self.tree_map = {}
             for i, tree in enumerate(trees):
                 size = len(tostring(tree.getroot()))
                 if size > self.max_flow_size:
-                    self.log('\tFound large tree #%d' % i)
+                    self.log.info('\tFound large tree #%s', i)
                     lt_found = True
                     self.split_trees = []
                     self.split_to_size(tree)
@@ -240,7 +240,7 @@ class FlowSplitter(object):
 
         self.was_split = len(self.trees) > 1
         if self.was_split:
-            self.log('\tSplit into %d parts' % len(self.trees))
+            self.log('\tSplit into %s parts', len(self.trees))
         self.commit()
 
     def split_on_page_breaks(self, orig_tree):
@@ -259,7 +259,7 @@ class FlowSplitter(object):
                 tree = self.trees[i]
                 elem = pattern(tree)
                 if elem:
-                    self.log.debug('\t\tSplitting on page-break at id=%s' %
+                    self.log.debug('\t\tSplitting on page-break at id=%s',
                                    elem[0].get('id'))
                     before_tree, after_tree = self.do_split(tree, elem[0],
                                                             before)
@@ -322,10 +322,10 @@ class FlowSplitter(object):
         return True
 
     def split_text(self, text, root, size):
-        self.log.debug('\t\t\tSplitting text of length: %d' % len(text))
+        self.log.debug('\t\t\tSplitting text of length: %d', len(text))
         rest = text.replace('\r', '')
         parts = re.split('\n\n', rest)
-        self.log.debug('\t\t\t\tFound %d parts' % len(parts))
+        self.log.debug('\t\t\t\tFound %d parts', len(parts))
         if max(map(len, parts)) > size:
             raise SplitError('Cannot split as file contains a <pre> tag '
                              'with a very large paragraph', root)
@@ -364,7 +364,7 @@ class FlowSplitter(object):
         split_point, before = self.find_split_point(root)
         if split_point is None:
             raise SplitError(self.item.href, root)
-        self.log.debug('\t\t\tSplit point:', split_point.tag,
+        self.log.debug('\t\t\tSplit point: %s %s', split_point.tag,
                        tree.getpath(split_point))
 
         trees = self.do_split(tree, split_point, before)
@@ -380,10 +380,10 @@ class FlowSplitter(object):
                 continue
             elif size <= self.max_flow_size:
                 self.split_trees.append(t)
-                self.log.debug('\t\t\tCommitted sub-tree #%d (%d KB)' %
-                               (len(self.split_trees), size/1024.))
+                self.log.debug('\t\t\tCommitted sub-tree #%s (%s KB)',
+                               len(self.split_trees), size/1024.)
             else:
-                self.log.debug('\t\t\tSplit tree still too large: %d KB' %
+                self.log.debug('\t\t\tSplit tree still too large: %d KB',
                                size/1024)
                 self.split_to_size(t)
 
diff --git a/ebook_converter/ebooks/oeb/transforms/structure.py b/ebook_converter/ebooks/oeb/transforms/structure.py
index 3d06fce..519cb8e 100644
--- a/ebook_converter/ebooks/oeb/transforms/structure.py
+++ b/ebook_converter/ebooks/oeb/transforms/structure.py
@@ -51,7 +51,7 @@ class DetectStructure(object):
         self.log = oeb.log
         self.oeb = oeb
         self.opts = opts
-        self.log('Detecting structure...')
+        self.log.info('Detecting structure...')
 
         self.detect_chapters()
         if self.oeb.auto_generated_toc or opts.use_auto_toc:
@@ -67,15 +67,15 @@ class DetectStructure(object):
                 self.oeb.toc = orig_toc
             else:
                 self.oeb.auto_generated_toc = True
-                self.log('Auto generated TOC with %d entries.' %
-                         self.oeb.toc.count())
+                self.log.info('Auto generated TOC with %s entries.',
+                              self.oeb.toc.count())
 
         if opts.toc_filter is not None:
             regexp = re.compile(opts.toc_filter)
             for node in list(self.oeb.toc.iter()):
                 if not node.title or regexp.search(node.title) is not None:
-                    self.log('Filtering', node.title if node.title else
-                             'empty node', 'from TOC')
+                    self.log.info('Filtering %s from TOC', node.title if
+                                  node.title else 'empty node')
                     self.oeb.toc.remove(node)
 
         if opts.page_breaks_before is not None:
@@ -112,8 +112,8 @@ class DetectStructure(object):
         try:
             expr = XPath(expr)
         except Exception:
-            self.log.warn('Invalid start reading at XPath expression, '
-                          'ignoring: %s' % expr)
+            self.log.warning('Invalid start reading at XPath expression, '
+                             'ignoring: %s', expr)
             return
         for item in self.oeb.spine:
             if not hasattr(item.data, 'xpath'):
@@ -129,11 +129,11 @@ class DetectStructure(object):
                 if 'text' in self.oeb.guide:
                     self.oeb.guide.remove('text')
                 self.oeb.guide.add('text', 'Start', item.href+'#'+eid)
-                self.log('Setting start reading at position to %s in %s' %
-                         (self.opts.start_reading_at, item.href))
+                self.log.info('Setting start reading at position to %s in %s',
+                              self.opts.start_reading_at, item.href)
                 return
-        self.log.warn("Failed to find start reading at position: %s" %
-                      self.opts.start_reading_at)
+        self.log.warning("Failed to find start reading at position: %s",
+                         self.opts.start_reading_at)
 
     def get_toc_parts_for_xpath(self, expr):
         # if an attribute is selected by the xpath expr then truncate it
@@ -155,8 +155,8 @@ class DetectStructure(object):
                 len(ans)
                 return ans
             except Exception:
-                self.log.warn('Invalid chapter expression, ignoring: %s' %
-                              expr)
+                self.log.warning('Invalid chapter expression, ignoring: %s',
+                                 expr)
                 return []
 
         if self.opts.chapter:
@@ -175,7 +175,7 @@ class DetectStructure(object):
                 c[item] += 1
                 text = base.xml2text(elem).strip()
                 text = re.sub(r'\s+', ' ', text.strip())
-                self.log('\tDetected chapter:', text[:50])
+                self.log.info('\tDetected chapter: %s', text[:50])
                 if chapter_mark == 'none':
                     continue
                 if chapter_mark == 'rule':
@@ -221,7 +221,7 @@ class DetectStructure(object):
                 try:
                     purl = urllib.parse.urlparse(href)
                 except ValueError:
-                    self.log.warning('Ignoring malformed URL:', href)
+                    self.log.warning('Ignoring malformed URL: %s', href)
                     continue
                 if not purl[0] or purl[0] == 'file':
                     href, frag = purl.path, purl.fragment
@@ -240,13 +240,14 @@ class DetectStructure(object):
                                 play_order=self.oeb.toc.next_play_order())
                             num += 1
                         except ValueError:
-                            self.oeb.log.exception('Failed to process link: '
-                                                   '%r' % href)
+                            self.oeb.log.critical('Failed to process link: %s',
+                                                  href)
                             # Most likely an incorrectly URL encoded link
                             continue
                         if self.opts.max_toc_links > 0 and \
                                 num >= self.opts.max_toc_links:
-                            self.log('Maximum TOC links reached, stopping.')
+                            self.log.info('Maximum TOC links reached, '
+                                          'stopping.')
                             return
 
     def elem_to_link(self, item, elem, title_attribute, counter):
@@ -277,7 +278,7 @@ class DetectStructure(object):
                 len(ans)
                 return ans
             except Exception:
-                self.log.warn('Invalid ToC expression, ignoring: %s' % expr)
+                self.log.warning('Invalid ToC expression, ignoring: %s', expr)
                 return []
 
         for document in self.oeb.spine:
diff --git a/ebook_converter/ebooks/oeb/transforms/subset.py b/ebook_converter/ebooks/oeb/transforms/subset.py
index 63044ae..f3b9f7d 100644
--- a/ebook_converter/ebooks/oeb/transforms/subset.py
+++ b/ebook_converter/ebooks/oeb/transforms/subset.py
@@ -5,11 +5,6 @@ from ebook_converter.utils.fonts.sfnt.subset import subset, NoGlyphs, Unsupporte
 from ebook_converter.tinycss.fonts3 import parse_font_family
 
 
-__license__ = 'GPL v3'
-__copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
 def get_font_properties(rule, default=None):
     '''
     Given a CSS rule, extract normalized font properties from
@@ -19,7 +14,7 @@ def get_font_properties(rule, default=None):
     props = {}
     s = rule.style
     for q in ('font-family', 'src', 'font-weight', 'font-stretch',
-            'font-style'):
+              'font-style'):
         g = 'uri' if q == 'src' else 'value'
         try:
             val = s.getProperty(q).propertyValue[0]
@@ -149,18 +144,19 @@ class SubsetFonts(object):
 
         for font in fonts.values():
             if not font['chars']:
-                self.log('The font %s is unused. Removing it.'%font['src'])
+                self.log('The font %s is unused. Removing it.', font['src'])
                 remove(font)
                 continue
             try:
                 raw, old_stats, new_stats = subset(font['item'].data, font['chars'])
             except NoGlyphs:
-                self.log('The font %s has no used glyphs. Removing it.'%font['src'])
+                self.log('The font %s has no used glyphs. Removing it.',
+                         font['src'])
                 remove(font)
                 continue
             except UnsupportedFont as e:
-                self.log.warn('The font %s is unsupported for subsetting. %s'%(
-                    font['src'], e))
+                self.log.warning('The font %s is unsupported for subsetting. '
+                                 '%s', font['src'], e)
                 sz = len(font['item'].data)
                 totals[0] += sz
                 totals[1] += sz
@@ -168,16 +164,16 @@ class SubsetFonts(object):
                 font['item'].data = raw
                 nlen = sum(new_stats.values())
                 olen = sum(old_stats.values())
-                self.log('Decreased the font %s to %.1f%% of its original size'%
-                        (font['src'], nlen/olen *100))
+                self.log('Decreased the font %s to %.1f%% of its original '
+                         'size', font['src'], nlen/olen * 100)
                 totals[0] += nlen
                 totals[1] += olen
 
             font['item'].unload_data_from_memory()
 
         if totals[0]:
-            self.log('Reduced total font size to %.1f%% of original'%
-                    (totals[0]/totals[1] * 100))
+            self.log('Reduced total font size to %.1f%% of original',
+                     totals[0]/totals[1] * 100)
 
     def find_embedded_fonts(self):
         '''
diff --git a/ebook_converter/ebooks/pdb/ereader/reader132.py b/ebook_converter/ebooks/pdb/ereader/reader132.py
index 1e0b8af..bc5241b 100644
--- a/ebook_converter/ebooks/pdb/ereader/reader132.py
+++ b/ebook_converter/ebooks/pdb/ereader/reader132.py
@@ -112,7 +112,7 @@ class Reader132(FormatReader):
 
         pml = ''
         for i in range(1, self.header_record.num_text_pages + 1):
-            self.log.debug('Extracting text page %i' % i)
+            self.log.debug('Extracting text page %s', i)
             pml += self.get_text_page(i)
         hizer = PML_HTMLizer()
         html += hizer.parse_pml(pml, 'index.html')
@@ -123,7 +123,7 @@ class Reader132(FormatReader):
             footnoteids = re.findall(
                 '\\w+(?=\x00)', self.section_data(self.header_record.footnote_offset).decode('cp1252' if self.encoding is None else self.encoding))
             for fid, i in enumerate(range(self.header_record.footnote_offset + 1, self.header_record.footnote_offset + self.header_record.footnote_count)):
-                self.log.debug('Extracting footnote page %i' % i)
+                self.log.debug('Extracting footnote page %s', i)
                 if fid < len(footnoteids):
                     fid = footnoteids[fid]
                 else:
@@ -135,7 +135,7 @@ class Reader132(FormatReader):
             sidebarids = re.findall(
                 '\\w+(?=\x00)', self.section_data(self.header_record.sidebar_offset).decode('cp1252' if self.encoding is None else self.encoding))
             for sid, i in enumerate(range(self.header_record.sidebar_offset + 1, self.header_record.sidebar_offset + self.header_record.sidebar_count)):
-                self.log.debug('Extracting sidebar page %i' % i)
+                self.log.debug('Extracting sidebar page %s', i)
                 if sid < len(sidebarids):
                     sid = sidebarids[sid]
                 else:
@@ -157,7 +157,7 @@ class Reader132(FormatReader):
                 name, img = self.get_image(self.header_record.image_data_offset + i)
                 images.append(name)
                 with open(name, 'wb') as imgf:
-                    self.log.debug('Writing image %s to images/' % name)
+                    self.log.debug('Writing image %s to images/', name)
                     imgf.write(img)
 
         opf_path = self.create_opf(output_dir, images, toc)
diff --git a/ebook_converter/ebooks/pdb/ereader/reader202.py b/ebook_converter/ebooks/pdb/ereader/reader202.py
index e7237fd..304fcca 100644
--- a/ebook_converter/ebooks/pdb/ereader/reader202.py
+++ b/ebook_converter/ebooks/pdb/ereader/reader202.py
@@ -87,7 +87,7 @@ class Reader202(FormatReader):
 
         pml = ''
         for i in range(1, self.header_record.num_text_pages + 1):
-            self.log.debug('Extracting text page %i' % i)
+            self.log.debug('Extracting text page %s', i)
             pml += self.get_text_page(i)
 
         title = self.mi.title
@@ -111,7 +111,7 @@ class Reader202(FormatReader):
                 if name:
                     images.append(name)
                     with open(name, 'wb') as imgf:
-                        self.log.debug('Writing image %s to images/' % name)
+                        self.log.debug('Writing image %s to images/', name)
                         imgf.write(img)
 
         opf_path = self.create_opf(output_dir, images)
diff --git a/ebook_converter/ebooks/pdb/haodoo/reader.py b/ebook_converter/ebooks/pdb/haodoo/reader.py
index ec611f5..6844b65 100644
--- a/ebook_converter/ebooks/pdb/haodoo/reader.py
+++ b/ebook_converter/ebooks/pdb/haodoo/reader.py
@@ -116,9 +116,9 @@ class Reader(FormatReader):
     def extract_content(self, output_dir):
         txt = ''
 
-        self.log.info(u'Decompressing text...')
+        self.log.info('Decompressing text...')
         for i in range(1, self.header_record.num_records + 1):
-            self.log.debug(u'\tDecompressing text section %i' % i)
+            self.log.debug('\tDecompressing text section %s', i)
             title = self.header_record.chapter_titles[i-1]
             lines = []
             title_added = False
@@ -135,7 +135,7 @@ class Reader(FormatReader):
                 lines.insert(0, '<h1 class="chapter">' + title + '</h1>\n')
             txt += '\n'.join(lines)
 
-        self.log.info(u'Converting text to OEB...')
+        self.log.info('Converting text to OEB...')
         html = HTML_TEMPLATE % (self.header_record.title, txt)
         with open(os.path.join(output_dir, 'index.html'), 'wb') as index:
             index.write(html.encode('utf-8'))
diff --git a/ebook_converter/ebooks/pdb/palmdoc/reader.py b/ebook_converter/ebooks/pdb/palmdoc/reader.py
index c6f057b..bafdb0c 100644
--- a/ebook_converter/ebooks/pdb/palmdoc/reader.py
+++ b/ebook_converter/ebooks/pdb/palmdoc/reader.py
@@ -55,7 +55,7 @@ class Reader(FormatReader):
 
         self.log.info('Decompressing text...')
         for i in range(1, self.header_record.num_records + 1):
-            self.log.debug('\tDecompressing text section %i' % i)
+            self.log.debug('\tDecompressing text section %s', i)
             raw_txt += self.decompress_text(i)
 
         self.log.info('Converting text to OEB...')
diff --git a/ebook_converter/ebooks/pdb/plucker/reader.py b/ebook_converter/ebooks/pdb/plucker/reader.py
index 5f43dc2..3eff90b 100644
--- a/ebook_converter/ebooks/pdb/plucker/reader.py
+++ b/ebook_converter/ebooks/pdb/plucker/reader.py
@@ -360,7 +360,8 @@ class Reader(FormatReader):
         # plugin assemble the order based on hyperlinks.
         with directory.CurrentDir(output_dir):
             for uid, num in self.uid_text_secion_number.items():
-                self.log.debug('Writing record with uid: %s as %s.html' % (uid, uid))
+                self.log.debug('Writing record with uid: %s as %s.html',
+                               uid, uid)
                 with open('%s.html' % uid, 'wb') as htmlf:
                     html = u'<html><body>'
                     section_header, section_data = self.sections[num]
@@ -393,11 +394,14 @@ class Reader(FormatReader):
                     try:
                         save_cover_data_to(idata, '%s.jpg' % uid, compression_quality=70)
                         images.add(uid)
-                        self.log.debug('Wrote image with uid %s to images/%s.jpg' % (uid, uid))
+                        self.log.debug('Wrote image with uid %s to '
+                                       'images/%s.jpg', uid, uid)
                     except Exception as e:
-                        self.log.error('Failed to write image with uid %s: %s' % (uid, e))
+                        self.log.error('Failed to write image with uid %s: %s',
+                                       uid, e)
                 else:
-                    self.log.error('Failed to write image with uid %s: No data.' % uid)
+                    self.log.error('Failed to write image with uid %s: '
+                                   'No data.', uid)
             # Composite images.
             # We're going to use the already compressed .jpg images here.
             for uid, num in self.uid_composite_image_section_number.items():
@@ -436,9 +440,11 @@ class Reader(FormatReader):
                             y_off += largest_height
                     with open('%s.jpg' % uid) as out:
                         out.write(canvas.export(compression_quality=70))
-                    self.log.debug('Wrote composite image with uid %s to images/%s.jpg' % (uid, uid))
+                    self.log.debug('Wrote composite image with uid %s to '
+                                   'images/%s.jpg', uid, uid)
                 except Exception as e:
-                    self.log.error('Failed to write composite image with uid %s: %s' % (uid, e))
+                    self.log.error('Failed to write composite image with '
+                                   'uid %s: %s', uid, e)
 
         # Run the HTML through the html processing plugin.
         from ebook_converter.customize.ui import plugin_for_input_format
diff --git a/ebook_converter/ebooks/pdb/ztxt/reader.py b/ebook_converter/ebooks/pdb/ztxt/reader.py
index 058157b..6efd45a 100644
--- a/ebook_converter/ebooks/pdb/ztxt/reader.py
+++ b/ebook_converter/ebooks/pdb/ztxt/reader.py
@@ -54,7 +54,7 @@ class Reader(FormatReader):
         if (self.header_record.flags & 0x01) == 0:
             raise zTXTError('Only compression method 1 (random access) is supported')
 
-        self.log.debug('Foud ztxt version: %i.%i' % (vmajor, vminor))
+        self.log.debug('Foud ztxt version: %s.%s', vmajor, vminor)
 
         # Initalize the decompressor
         self.uncompressor = zlib.decompressobj()
@@ -73,7 +73,7 @@ class Reader(FormatReader):
 
         self.log.info('Decompressing text...')
         for i in range(1, self.header_record.num_records + 1):
-            self.log.debug('\tDecompressing text section %i' % i)
+            self.log.debug('\tDecompressing text section %s', i)
             raw_txt += self.decompress_text(i)
 
         self.log.info('Converting text to OEB...')
diff --git a/ebook_converter/ebooks/txt/markdownml.py b/ebook_converter/ebooks/txt/markdownml.py
index 0b862ee..5cbfd0a 100644
--- a/ebook_converter/ebooks/txt/markdownml.py
+++ b/ebook_converter/ebooks/txt/markdownml.py
@@ -43,7 +43,8 @@ class MarkdownMLizer(OEB2HTML):
     def mlize_spine(self, oeb_book):
         output = ['']
         for item in oeb_book.spine:
-            self.log.debug('Converting %s to Markdown formatted TXT...' % item.href)
+            self.log.debug('Converting %s to Markdown formatted TXT...',
+                           item.href)
             self.rewrite_ids(item.data, item)
             rewrite_links(item.data, partial(self.rewrite_link, page=item))
             stylizer = Stylizer(item.data, item.href, oeb_book, self.opts, self.opts.output_profile)
diff --git a/ebook_converter/ebooks/txt/textileml.py b/ebook_converter/ebooks/txt/textileml.py
index 7b6f626..8e8aa23 100644
--- a/ebook_converter/ebooks/txt/textileml.py
+++ b/ebook_converter/ebooks/txt/textileml.py
@@ -58,7 +58,7 @@ class TextileMLizer(OEB2HTML):
     def mlize_spine(self, oeb_book):
         output = ['']
         for item in oeb_book.spine:
-            self.log.debug('Converting %s to Textile formatted TXT...' % item.href)
+            self.log.debug('Converting %s to Textile formatted TXT...', item.href)
             self.rewrite_ids(item.data, item)
             rewrite_links(item.data, partial(self.rewrite_link, page=item))
             stylizer = Stylizer(item.data, item.href, oeb_book, self.opts, self.opts.output_profile)
diff --git a/ebook_converter/ebooks/txt/txtml.py b/ebook_converter/ebooks/txt/txtml.py
index 9b17a11..a230f97 100644
--- a/ebook_converter/ebooks/txt/txtml.py
+++ b/ebook_converter/ebooks/txt/txtml.py
@@ -64,7 +64,7 @@ class TXTMLizer(object):
         output = [u'']
         output.append(self.get_toc())
         for item in self.oeb_book.spine:
-            self.log.debug('Converting %s to TXT...' % item.href)
+            self.log.debug('Converting %s to TXT...', item.href)
             for x in item.data.iterdescendants(etree.Comment):
                 if x.text and '--' in x.text:
                     x.text = x.text.replace('--', '__')