Removed isbytestring function

ebook_converter/ebooks/metadata/book/json_codec.py

@@ -9,7 +9,6 @@ from datetime import datetime, time
 from ebook_converter.ebooks.metadata.book import SERIALIZABLE_FIELDS
 from ebook_converter.constants_old import filesystem_encoding, preferred_encoding
 from ebook_converter.library.field_metadata import FieldMetadata
-from ebook_converter import isbytestring
 from ebook_converter.polyglot.builtins import as_bytes
 from ebook_converter.polyglot.binary import as_base64_unicode, from_base64_bytes
 
@@ -73,10 +72,10 @@ def object_to_unicode(obj, enc=preferred_encoding):
     def dec(x):
         return x.decode(enc, 'replace')
 
-    if isbytestring(obj):
+    if isinstance(obj, bytes):
         return dec(obj)
     if isinstance(obj, (list, tuple)):
-        return [dec(x) if isbytestring(x) else object_to_unicode(x) for x in obj]
+        return [dec(x) if isinstance(x, bytes) else object_to_unicode(x) for x in obj]
     if isinstance(obj, dict):
         ans = {}
         for k, v in obj.items():
@@ -163,7 +162,7 @@ class JsonCodec(object):
         value = book.get(key)
         if key == 'thumbnail':
             return encode_thumbnail(value)
-        elif isbytestring(value):  # str includes bytes
+        elif isinstance(value, bytes):  # str includes bytes
             enc = filesystem_encoding if key == 'lpath' else preferred_encoding
             return object_to_unicode(value, enc=enc)
         elif datatype == 'datetime':

ebook_converter/ebooks/metadata/html.py

@@ -11,7 +11,7 @@ from lxml.etree import Comment
 from ebook_converter.ebooks.metadata import string_to_authors, authors_to_string
 from ebook_converter.ebooks.metadata.book.base import Metadata
 from ebook_converter.ebooks.chardet import xml_to_unicode
-from ebook_converter import replace_entities, isbytestring
+from ebook_converter import replace_entities
 from ebook_converter.utils.date import parse_date, is_date_undefined
 
 
@@ -128,7 +128,7 @@ def get_metadata_(src, encoding=None):
     # Meta data definitions as in
     # https://www.mobileread.com/forums/showpost.php?p=712544&postcount=9
 
-    if isbytestring(src):
+    if isinstance(src, bytes):
         if not encoding:
             src = xml_to_unicode(src)[0]
         else:

ebook_converter/ebooks/metadata/meta.py

@@ -3,7 +3,6 @@ import os, re, collections
 from ebook_converter.utils.config import prefs
 from ebook_converter.constants_old import filesystem_encoding
 from ebook_converter.ebooks.metadata.opf2 import OPF
-from ebook_converter import isbytestring
 from ebook_converter.customize.ui import get_file_type_metadata, set_file_type_metadata
 from ebook_converter.ebooks.metadata import MetaInformation, string_to_authors
 
@@ -126,7 +125,7 @@ def set_metadata(stream, mi, stream_type='lrf', report_error=None):
 
 
 def metadata_from_filename(name, pat=None, fallback_pat=None):
-    if isbytestring(name):
+    if isinstance(name, bytes):
         name = name.decode(filesystem_encoding, 'replace')
     name = name.rpartition('.')[0]
     mi = MetaInformation(None, None)