Removed another unicode/string nonsense

ebook_converter/utils/date.py

@@ -6,13 +6,8 @@ from ebook_converter import strftime
 from ebook_converter.constants import iswindows, isosx, plugins, preferred_encoding
 from ebook_converter.utils.iso8601 import utc_tz, local_tz, UNDEFINED_DATE
 from ebook_converter.utils.localization import lcdata
-from ebook_converter.polyglot.builtins import native_string_type
 
 
-__license__ = 'GPL v3'
-__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
 _utc_tz = utc_tz
 _local_tz = local_tz
 
@@ -39,7 +34,7 @@ else:
         def first_index(raw, queries):
             for q in queries:
                 try:
-                    return raw.index(native_string_type(q))
+                    return raw.index(q)
                 except ValueError:
                     pass
             return -1
@@ -191,8 +186,7 @@ def isoformat(date_time, assume_utc=False, as_utc=True, sep='T'):
         date_time = date_time.replace(tzinfo=_utc_tz if assume_utc else
                 _local_tz)
     date_time = date_time.astimezone(_utc_tz if as_utc else _local_tz)
-    # native_string_type(sep) because isoformat barfs with unicode sep on python 2.x
-    return str(date_time.isoformat(native_string_type(sep)))
+    return str(date_time.isoformat(sep))
 
 
 def internal_iso_format_string():