[cleanup] Upgrade syntax

Using https://github.com/asottile/pyupgrade

1. `__future__` imports and `coding: utf-8` were removed
2. Files were rewritten with `pyupgrade --py36-plus --keep-percent-format`
3. f-strings were cherry-picked from `pyupgrade --py36-plus`

Extractors are left untouched (except removing header) to avoid unnecessary merge conflicts

CONTRIBUTING.md

@@ -178,7 +178,6 @@ ## Adding support for a new site
 1. Start with this simple template and save it to `yt_dlp/extractor/yourextractor.py`:
 
     ```python
-    # coding: utf-8
     from .common import InfoExtractor
     
     

devscripts/bash-completion.py

@@ -1,11 +1,9 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import os
 from os.path import dirname as dirn
 import sys
 
-sys.path.insert(0, dirn(dirn((os.path.abspath(__file__)))))
+sys.path.insert(0, dirn(dirn(os.path.abspath(__file__))))
 import yt_dlp
 
 BASH_COMPLETION_FILE = "completions/bash/yt-dlp"

devscripts/check-porn.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 """
 This script employs a VERY basic heuristic ('porn' in webpage.lower()) to check
 if we are not 'age_limit' tagging some porn site
@@ -29,7 +27,7 @@
         try:
             webpage = compat_urllib_request.urlopen(test['url'], timeout=10).read()
         except Exception:
-            print('\nFail: {0}'.format(test['name']))
+            print('\nFail: {}'.format(test['name']))
             continue
 
         webpage = webpage.decode('utf8', 'replace')
@@ -39,7 +37,7 @@
     elif METHOD == 'LIST':
         domain = compat_urllib_parse_urlparse(test['url']).netloc
         if not domain:
-            print('\nFail: {0}'.format(test['name']))
+            print('\nFail: {}'.format(test['name']))
             continue
         domain = '.'.join(domain.split('.')[-2:])
 
@@ -47,11 +45,11 @@
 
     if RESULT and ('info_dict' not in test or 'age_limit' not in test['info_dict']
                    or test['info_dict']['age_limit'] != 18):
-        print('\nPotential missing age_limit check: {0}'.format(test['name']))
+        print('\nPotential missing age_limit check: {}'.format(test['name']))
 
     elif not RESULT and ('info_dict' in test and 'age_limit' in test['info_dict']
                          and test['info_dict']['age_limit'] == 18):
-        print('\nPotential false negative: {0}'.format(test['name']))
+        print('\nPotential false negative: {}'.format(test['name']))
 
     else:
         sys.stdout.write('.')

devscripts/fish-completion.py

@@ -1,12 +1,10 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import optparse
 import os
 from os.path import dirname as dirn
 import sys
 
-sys.path.insert(0, dirn(dirn((os.path.abspath(__file__)))))
+sys.path.insert(0, dirn(dirn(os.path.abspath(__file__))))
 import yt_dlp
 from yt_dlp.utils import shell_quote
 

devscripts/generate_aes_testdata.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import codecs
 import subprocess
 

devscripts/lazy_load_template.py

@@ -1,4 +1,3 @@
-# coding: utf-8
 import re
 
 from ..utils import bug_reports_message, write_string

devscripts/make_contributing.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
-import io
 import optparse
 import re
 
@@ -16,7 +13,7 @@ def main():
 
     infile, outfile = args
 
-    with io.open(infile, encoding='utf-8') as inf:
+    with open(infile, encoding='utf-8') as inf:
         readme = inf.read()
 
     bug_text = re.search(
@@ -26,7 +23,7 @@ def main():
 
     out = bug_text + dev_text
 
-    with io.open(outfile, 'w', encoding='utf-8') as outf:
+    with open(outfile, 'w', encoding='utf-8') as outf:
         outf.write(out)
 
 

devscripts/make_issue_template.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import io
 import optparse
 
@@ -13,7 +11,7 @@ def main():
 
     infile, outfile = args
 
-    with io.open(infile, encoding='utf-8') as inf:
+    with open(infile, encoding='utf-8') as inf:
         issue_template_tmpl = inf.read()
 
     # Get the version from yt_dlp/version.py without importing the package
@@ -22,8 +20,9 @@ def main():
 
     out = issue_template_tmpl % {'version': locals()['__version__']}
 
-    with io.open(outfile, 'w', encoding='utf-8') as outf:
+    with open(outfile, 'w', encoding='utf-8') as outf:
         outf.write(out)
 
+
 if __name__ == '__main__':
     main()

devscripts/make_lazy_extractors.py

@@ -1,13 +1,10 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals, print_function
-
 from inspect import getsource
-import io
 import os
 from os.path import dirname as dirn
 import sys
 
-sys.path.insert(0, dirn(dirn((os.path.abspath(__file__)))))
+sys.path.insert(0, dirn(dirn(os.path.abspath(__file__))))
 
 lazy_extractors_filename = sys.argv[1] if len(sys.argv) > 1 else 'yt_dlp/extractor/lazy_extractors.py'
 if os.path.exists(lazy_extractors_filename):
@@ -25,7 +22,7 @@
 if os.path.exists(plugins_blocked_dirname):
     os.rename(plugins_blocked_dirname, plugins_dirname)
 
-with open('devscripts/lazy_load_template.py', 'rt') as f:
+with open('devscripts/lazy_load_template.py') as f:
     module_template = f.read()
 
 CLASS_PROPERTIES = ['ie_key', 'working', '_match_valid_url', 'suitable', '_match_id', 'get_temp_id']
@@ -72,7 +69,7 @@ def build_lazy_ie(ie, name):
 ordered_cls = []
 while classes:
     for c in classes[:]:
-        bases = set(c.__bases__) - set((object, InfoExtractor, SearchInfoExtractor))
+        bases = set(c.__bases__) - {object, InfoExtractor, SearchInfoExtractor}
         stop = False
         for b in bases:
             if b not in classes and b not in ordered_cls:
@@ -97,9 +94,9 @@ def build_lazy_ie(ie, name):
         names.append(name)
 
 module_contents.append(
-    '\n_ALL_CLASSES = [{0}]'.format(', '.join(names)))
+    '\n_ALL_CLASSES = [{}]'.format(', '.join(names)))
 
 module_src = '\n'.join(module_contents) + '\n'
 
-with io.open(lazy_extractors_filename, 'wt', encoding='utf-8') as f:
+with open(lazy_extractors_filename, 'wt', encoding='utf-8') as f:
     f.write(module_src)

devscripts/make_readme.py

@@ -2,10 +2,6 @@
 
 # yt-dlp --help | make_readme.py
 # This must be run in a console of correct width
-
-from __future__ import unicode_literals
-
-import io
 import sys
 import re
 
@@ -15,7 +11,7 @@
 if isinstance(helptext, bytes):
     helptext = helptext.decode('utf-8')
 
-with io.open(README_FILE, encoding='utf-8') as f:
+with open(README_FILE, encoding='utf-8') as f:
     oldreadme = f.read()
 
 header = oldreadme[:oldreadme.index('## General Options:')]
@@ -25,7 +21,7 @@
 options = re.sub(r'(?m)^  (\w.+)$', r'## \1', options)
 options = options + '\n'
 
-with io.open(README_FILE, 'w', encoding='utf-8') as f:
+with open(README_FILE, 'w', encoding='utf-8') as f:
     f.write(header)
     f.write(options)
     f.write(footer)

devscripts/make_supportedsites.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
-import io
 import optparse
 import os
 import sys
@@ -23,11 +20,11 @@ def main():
 
     def gen_ies_md(ies):
         for ie in ies:
-            ie_md = '**{0}**'.format(ie.IE_NAME)
+            ie_md = f'**{ie.IE_NAME}**'
             if ie.IE_DESC is False:
                 continue
             if ie.IE_DESC is not None:
-                ie_md += ': {0}'.format(ie.IE_DESC)
+                ie_md += f': {ie.IE_DESC}'
             search_key = getattr(ie, 'SEARCH_KEY', None)
             if search_key is not None:
                 ie_md += f'; "{ie.SEARCH_KEY}:" prefix'
@@ -40,7 +37,7 @@ def gen_ies_md(ies):
         ' - ' + md + '\n'
         for md in gen_ies_md(ies))
 
-    with io.open(outfile, 'w', encoding='utf-8') as outf:
+    with open(outfile, 'w', encoding='utf-8') as outf:
         outf.write(out)
 
 

devscripts/prepare_manpage.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
-import io
 import optparse
 import os.path
 import re
@@ -32,14 +29,14 @@ def main():
 
     outfile, = args
 
-    with io.open(README_FILE, encoding='utf-8') as f:
+    with open(README_FILE, encoding='utf-8') as f:
         readme = f.read()
 
     readme = filter_excluded_sections(readme)
     readme = move_sections(readme)
     readme = filter_options(readme)
 
-    with io.open(outfile, 'w', encoding='utf-8') as outf:
+    with open(outfile, 'w', encoding='utf-8') as outf:
         outf.write(PREFIX + readme)
 
 

devscripts/update-formulae.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import json
 import os
 import re
@@ -27,7 +25,7 @@
 sha256sum = tarball_file['digests']['sha256']
 url = tarball_file['url']
 
-with open(filename, 'r') as r:
+with open(filename) as r:
     formulae_text = r.read()
 
 formulae_text = re.sub(r'sha256 "[0-9a-f]*?"', 'sha256 "%s"' % sha256sum, formulae_text)

devscripts/update-version.py

@@ -4,7 +4,7 @@
 import subprocess
 
 
-with open('yt_dlp/version.py', 'rt') as f:
+with open('yt_dlp/version.py') as f:
     exec(compile(f.read(), 'yt_dlp/version.py', 'exec'))
 old_version = locals()['__version__']
 

devscripts/zsh-completion.py

@@ -1,11 +1,9 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import os
 from os.path import dirname as dirn
 import sys
 
-sys.path.insert(0, dirn(dirn((os.path.abspath(__file__)))))
+sys.path.insert(0, dirn(dirn(os.path.abspath(__file__))))
 import yt_dlp
 
 ZSH_COMPLETION_FILE = "completions/zsh/_yt-dlp"

pyinst.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
 import os
 import platform
 import sys

setup.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
 import os.path
 import warnings
 import sys

test/helper.py

@@ -1,7 +1,4 @@
-from __future__ import unicode_literals
-
 import errno
-import io
 import hashlib
 import json
 import os.path
@@ -35,10 +32,10 @@ def get_params(override=None):
                                    'parameters.json')
     LOCAL_PARAMETERS_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)),
                                          'local_parameters.json')
-    with io.open(PARAMETERS_FILE, encoding='utf-8') as pf:
+    with open(PARAMETERS_FILE, encoding='utf-8') as pf:
         parameters = json.load(pf)
     if os.path.exists(LOCAL_PARAMETERS_FILE):
-        with io.open(LOCAL_PARAMETERS_FILE, encoding='utf-8') as pf:
+        with open(LOCAL_PARAMETERS_FILE, encoding='utf-8') as pf:
             parameters.update(json.load(pf))
     if override:
         parameters.update(override)
@@ -63,7 +60,7 @@ def report_warning(message):
         _msg_header = '\033[0;33mWARNING:\033[0m'
     else:
         _msg_header = 'WARNING:'
-    output = '%s %s\n' % (_msg_header, message)
+    output = f'{_msg_header} {message}\n'
     if 'b' in getattr(sys.stderr, 'mode', ''):
         output = output.encode(preferredencoding())
     sys.stderr.write(output)
@@ -74,7 +71,7 @@ def __init__(self, override=None):
         # Different instances of the downloader can't share the same dictionary
         # some test set the "sublang" parameter, which would break the md5 checks.
         params = get_params(override=override)
-        super(FakeYDL, self).__init__(params, auto_init=False)
+        super().__init__(params, auto_init=False)
         self.result = []
 
     def to_screen(self, s, skip_eol=None):
@@ -99,8 +96,7 @@ def report_warning(self, message):
 
 def gettestcases(include_onlymatching=False):
     for ie in yt_dlp.extractor.gen_extractors():
-        for tc in ie.get_testcases(include_onlymatching):
+        yield from ie.get_testcases(include_onlymatching)
-            yield tc
 
 
 md5 = lambda s: hashlib.md5(s.encode('utf-8')).hexdigest()
@@ -113,33 +109,30 @@ def expect_value(self, got, expected, field):
 
         self.assertTrue(
             isinstance(got, compat_str),
-            'Expected a %s object, but got %s for field %s' % (
+            f'Expected a {compat_str.__name__} object, but got {type(got).__name__} for field {field}')
-                compat_str.__name__, type(got).__name__, field))
         self.assertTrue(
             match_rex.match(got),
-            'field %s (value: %r) should match %r' % (field, got, match_str))
+            f'field {field} (value: {got!r}) should match {match_str!r}')
     elif isinstance(expected, compat_str) and expected.startswith('startswith:'):
         start_str = expected[len('startswith:'):]
         self.assertTrue(
             isinstance(got, compat_str),
-            'Expected a %s object, but got %s for field %s' % (
+            f'Expected a {compat_str.__name__} object, but got {type(got).__name__} for field {field}')
-                compat_str.__name__, type(got).__name__, field))
         self.assertTrue(
             got.startswith(start_str),
-            'field %s (value: %r) should start with %r' % (field, got, start_str))
+            f'field {field} (value: {got!r}) should start with {start_str!r}')
     elif isinstance(expected, compat_str) and expected.startswith('contains:'):
         contains_str = expected[len('contains:'):]
         self.assertTrue(
             isinstance(got, compat_str),
-            'Expected a %s object, but got %s for field %s' % (
+            f'Expected a {compat_str.__name__} object, but got {type(got).__name__} for field {field}')
-                compat_str.__name__, type(got).__name__, field))
         self.assertTrue(
             contains_str in got,
-            'field %s (value: %r) should contain %r' % (field, got, contains_str))
+            f'field {field} (value: {got!r}) should contain {contains_str!r}')
     elif isinstance(expected, type):
         self.assertTrue(
             isinstance(got, expected),
-            'Expected type %r for field %s, but got value %r of type %r' % (expected, field, got, type(got)))
+            f'Expected type {expected!r} for field {field}, but got value {got!r} of type {type(got)!r}')
     elif isinstance(expected, dict) and isinstance(got, dict):
         expect_dict(self, got, expected)
     elif isinstance(expected, list) and isinstance(got, list):
@@ -159,13 +152,12 @@ def expect_value(self, got, expected, field):
         if isinstance(expected, compat_str) and expected.startswith('md5:'):
             self.assertTrue(
                 isinstance(got, compat_str),
-                'Expected field %s to be a unicode object, but got value %r of type %r' % (field, got, type(got)))
+                f'Expected field {field} to be a unicode object, but got value {got!r} of type {type(got)!r}')
             got = 'md5:' + md5(got)
         elif isinstance(expected, compat_str) and re.match(r'^(?:min|max)?count:\d+', expected):
             self.assertTrue(
                 isinstance(got, (list, dict)),
-                'Expected field %s to be a list or a dict, but it is of type %s' % (
+                f'Expected field {field} to be a list or a dict, but it is of type {type(got).__name__}')
-                    field, type(got).__name__))
             op, _, expected_num = expected.partition(':')
             expected_num = int(expected_num)
             if op == 'mincount':
@@ -185,7 +177,7 @@ def expect_value(self, got, expected, field):
             return
         self.assertEqual(
             expected, got,
-            'Invalid value for field %s, expected %r, got %r' % (field, expected, got))
+            f'Invalid value for field {field}, expected {expected!r}, got {got!r}')
 
 
 def expect_dict(self, got_dict, expected_dict):
@@ -260,13 +252,13 @@ def _repr(v):
         info_dict_str = ''
         if len(missing_keys) != len(expected_dict):
             info_dict_str += ''.join(
-                '    %s: %s,\n' % (_repr(k), _repr(v))
+                f'    {_repr(k)}: {_repr(v)},\n'
                 for k, v in test_info_dict.items() if k not in missing_keys)
 
             if info_dict_str:
                 info_dict_str += '\n'
         info_dict_str += ''.join(
-            '    %s: %s,\n' % (_repr(k), _repr(test_info_dict[k]))
+            f'    {_repr(k)}: {_repr(test_info_dict[k])},\n'
             for k in missing_keys)
         write_string(
             '\n\'info_dict\': {\n' + info_dict_str + '},\n', out=sys.stderr)
@@ -295,21 +287,21 @@ def assertRegexpMatches(self, text, regexp, msg=None):
 def assertGreaterEqual(self, got, expected, msg=None):
     if not (got >= expected):
         if msg is None:
-            msg = '%r not greater than or equal to %r' % (got, expected)
+            msg = f'{got!r} not greater than or equal to {expected!r}'
         self.assertTrue(got >= expected, msg)
 
 
 def assertLessEqual(self, got, expected, msg=None):
     if not (got <= expected):
         if msg is None:
-            msg = '%r not less than or equal to %r' % (got, expected)
+            msg = f'{got!r} not less than or equal to {expected!r}'
         self.assertTrue(got <= expected, msg)
 
 
 def assertEqual(self, got, expected, msg=None):
     if not (got == expected):
         if msg is None:
-            msg = '%r not equal to %r' % (got, expected)
+            msg = f'{got!r} not equal to {expected!r}'
         self.assertTrue(got == expected, msg)
 
 

test/test_InfoExtractor.py

@@ -1,9 +1,5 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
-import io
 import os
 import sys
 import unittest
@@ -1011,8 +1007,7 @@ def test_parse_m3u8_formats(self):
         ]
 
         for m3u8_file, m3u8_url, expected_formats, expected_subs in _TEST_CASES:
-            with io.open('./test/testdata/m3u8/%s.m3u8' % m3u8_file,
+            with open('./test/testdata/m3u8/%s.m3u8' % m3u8_file, encoding='utf-8') as f:
-                         mode='r', encoding='utf-8') as f:
                 formats, subs = self.ie._parse_m3u8_formats_and_subtitles(
                     f.read(), m3u8_url, ext='mp4')
                 self.ie._sort_formats(formats)
@@ -1357,8 +1352,7 @@ def test_parse_mpd_formats(self):
         ]
 
         for mpd_file, mpd_url, mpd_base_url, expected_formats, expected_subtitles in _TEST_CASES:
-            with io.open('./test/testdata/mpd/%s.mpd' % mpd_file,
+            with open('./test/testdata/mpd/%s.mpd' % mpd_file, encoding='utf-8') as f:
-                         mode='r', encoding='utf-8') as f:
                 formats, subtitles = self.ie._parse_mpd_formats_and_subtitles(
                     compat_etree_fromstring(f.read().encode('utf-8')),
                     mpd_base_url=mpd_base_url, mpd_url=mpd_url)
@@ -1549,8 +1543,7 @@ def test_parse_ism_formats(self):
         ]
 
         for ism_file, ism_url, expected_formats, expected_subtitles in _TEST_CASES:
-            with io.open('./test/testdata/ism/%s.Manifest' % ism_file,
+            with open('./test/testdata/ism/%s.Manifest' % ism_file, encoding='utf-8') as f:
-                         mode='r', encoding='utf-8') as f:
                 formats, subtitles = self.ie._parse_ism_formats_and_subtitles(
                     compat_etree_fromstring(f.read().encode('utf-8')), ism_url=ism_url)
                 self.ie._sort_formats(formats)
@@ -1576,8 +1569,7 @@ def test_parse_f4m_formats(self):
         ]
 
         for f4m_file, f4m_url, expected_formats in _TEST_CASES:
-            with io.open('./test/testdata/f4m/%s.f4m' % f4m_file,
+            with open('./test/testdata/f4m/%s.f4m' % f4m_file, encoding='utf-8') as f:
-                         mode='r', encoding='utf-8') as f:
                 formats = self.ie._parse_f4m_formats(
                     compat_etree_fromstring(f.read().encode('utf-8')),
                     f4m_url, None)
@@ -1624,8 +1616,7 @@ def test_parse_xspf(self):
         ]
 
         for xspf_file, xspf_url, expected_entries in _TEST_CASES:
-            with io.open('./test/testdata/xspf/%s.xspf' % xspf_file,
+            with open('./test/testdata/xspf/%s.xspf' % xspf_file, encoding='utf-8') as f:
-                         mode='r', encoding='utf-8') as f:
                 entries = self.ie._parse_xspf(
                     compat_etree_fromstring(f.read().encode('utf-8')),
                     xspf_file, xspf_url=xspf_url, xspf_base_url=xspf_url)

test/test_YoutubeDL.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -25,7 +21,7 @@
 
 class YDL(FakeYDL):
     def __init__(self, *args, **kwargs):
-        super(YDL, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.downloaded_info_dicts = []
         self.msgs = []
 
@@ -551,11 +547,11 @@ def test_subtitles(self):
         def s_formats(lang, autocaption=False):
             return [{
                 'ext': ext,
-                'url': 'http://localhost/video.%s.%s' % (lang, ext),
+                'url': f'http://localhost/video.{lang}.{ext}',
                 '_auto': autocaption,
             } for ext in ['vtt', 'srt', 'ass']]
-        subtitles = dict((l, s_formats(l)) for l in ['en', 'fr', 'es'])
+        subtitles = {l: s_formats(l) for l in ['en', 'fr', 'es']}
-        auto_captions = dict((l, s_formats(l, True)) for l in ['it', 'pt', 'es'])
+        auto_captions = {l: s_formats(l, True) for l in ['it', 'pt', 'es']}
         info_dict = {
             'id': 'test',
             'title': 'Test',
@@ -580,7 +576,7 @@ def get_info(params={}):
         result = get_info({'writesubtitles': True})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['en']))
+        self.assertEqual(set(subs.keys()), {'en'})
         self.assertTrue(subs['en'].get('data') is None)
         self.assertEqual(subs['en']['ext'], 'ass')
 
@@ -591,39 +587,39 @@ def get_info(params={}):
         result = get_info({'writesubtitles': True, 'subtitleslangs': ['es', 'fr', 'it']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['es', 'fr']))
+        self.assertEqual(set(subs.keys()), {'es', 'fr'})
 
         result = get_info({'writesubtitles': True, 'subtitleslangs': ['all', '-en']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['es', 'fr']))
+        self.assertEqual(set(subs.keys()), {'es', 'fr'})
 
         result = get_info({'writesubtitles': True, 'subtitleslangs': ['en', 'fr', '-en']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['fr']))
+        self.assertEqual(set(subs.keys()), {'fr'})
 
         result = get_info({'writesubtitles': True, 'subtitleslangs': ['-en', 'en']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['en']))
+        self.assertEqual(set(subs.keys()), {'en'})
 
         result = get_info({'writesubtitles': True, 'subtitleslangs': ['e.+']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['es', 'en']))
+        self.assertEqual(set(subs.keys()), {'es', 'en'})
 
         result = get_info({'writesubtitles': True, 'writeautomaticsub': True, 'subtitleslangs': ['es', 'pt']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['es', 'pt']))
+        self.assertEqual(set(subs.keys()), {'es', 'pt'})
         self.assertFalse(subs['es']['_auto'])
         self.assertTrue(subs['pt']['_auto'])
 
         result = get_info({'writeautomaticsub': True, 'subtitleslangs': ['es', 'pt']})
         subs = result['requested_subtitles']
         self.assertTrue(subs)
-        self.assertEqual(set(subs.keys()), set(['es', 'pt']))
+        self.assertEqual(set(subs.keys()), {'es', 'pt'})
         self.assertTrue(subs['es']['_auto'])
         self.assertTrue(subs['pt']['_auto'])
 
@@ -1082,7 +1078,7 @@ def test_ignoreerrors_for_playlist_with_url_transparent_iterable_entries(self):
 
         class _YDL(YDL):
             def __init__(self, *args, **kwargs):
-                super(_YDL, self).__init__(*args, **kwargs)
+                super().__init__(*args, **kwargs)
 
             def trouble(self, s, tb=None):
                 pass

test/test_YoutubeDLCookieJar.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 import os
 import re
 import sys

test/test_aes.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_age_restriction.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_all_urls.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -81,11 +78,11 @@ def test_no_duplicates(self):
             url = tc['url']
             for ie in ies:
                 if type(ie).__name__ in ('GenericIE', tc['name'] + 'IE'):
-                    self.assertTrue(ie.suitable(url), '%s should match URL %r' % (type(ie).__name__, url))
+                    self.assertTrue(ie.suitable(url), f'{type(ie).__name__} should match URL {url!r}')
                 else:
                     self.assertFalse(
                         ie.suitable(url),
-                        '%s should not match URL %r . That URL belongs to %s.' % (type(ie).__name__, url, tc['name']))
+                        f'{type(ie).__name__} should not match URL {url!r} . That URL belongs to {tc["name"]}.')
 
     def test_keywords(self):
         self.assertMatch(':ytsubs', ['youtube:subscriptions'])
@@ -120,7 +117,7 @@ def test_no_duplicated_ie_names(self):
         for (ie_name, ie_list) in name_accu.items():
             self.assertEqual(
                 len(ie_list), 1,
-                'Multiple extractors with the same IE_NAME "%s" (%s)' % (ie_name, ', '.join(ie_list)))
+                f'Multiple extractors with the same IE_NAME "{ie_name}" ({", ".join(ie_list)})')
 
 
 if __name__ == '__main__':

test/test_cache.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 import shutil
 
 # Allow direct execution

test/test_compat.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -48,7 +44,7 @@ def test_all_present(self):
         all_names = yt_dlp.compat.__all__
         present_names = set(filter(
             lambda c: '_' in c and not c.startswith('_'),
-            dir(yt_dlp.compat))) - set(['unicode_literals'])
+            dir(yt_dlp.compat))) - {'unicode_literals'}
         self.assertEqual(all_names, sorted(present_names))
 
     def test_compat_urllib_parse_unquote(self):

test/test_download.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -21,7 +18,6 @@
 
 
 import hashlib
-import io
 import json
 import socket
 
@@ -46,7 +42,7 @@ class YoutubeDL(yt_dlp.YoutubeDL):
     def __init__(self, *args, **kwargs):
         self.to_stderr = self.to_screen
         self.processed_info_dicts = []
-        super(YoutubeDL, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def report_warning(self, message):
         # Don't accept warnings during tests
@@ -54,7 +50,7 @@ def report_warning(self, message):
 
     def process_info(self, info_dict):
         self.processed_info_dicts.append(info_dict.copy())
-        return super(YoutubeDL, self).process_info(info_dict)
+        return super().process_info(info_dict)
 
 
 def _file_md5(fn):
@@ -80,7 +76,7 @@ def __str__(self):
 
         def strclass(cls):
             """From 2.7's unittest; 2.6 had _strclass so we can't import it."""
-            return '%s.%s' % (cls.__module__, cls.__name__)
+            return f'{cls.__module__}.{cls.__name__}'
 
         add_ie = getattr(self, self._testMethodName).add_ie
         return '%s (%s)%s:' % (self._testMethodName,
@@ -179,7 +175,7 @@ def try_rm_tcs_files(tcs=None):
                         report_warning('%s failed due to network errors, skipping...' % tname)
                         return
 
-                    print('Retrying: {0} failed tries\n\n##########\n\n'.format(try_num))
+                    print(f'Retrying: {try_num} failed tries\n\n##########\n\n')
 
                     try_num += 1
                 else:
@@ -245,7 +241,7 @@ def try_rm_tcs_files(tcs=None):
                 self.assertTrue(
                     os.path.exists(info_json_fn),
                     'Missing info file %s' % info_json_fn)
-                with io.open(info_json_fn, encoding='utf-8') as infof:
+                with open(info_json_fn, encoding='utf-8') as infof:
                     info_dict = json.load(infof)
                 expect_info_dict(self, info_dict, tc.get('info_dict', {}))
         finally:

test/test_downloader_http.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import re
@@ -66,7 +63,7 @@ def do_GET(self):
             assert False
 
 
-class FakeLogger(object):
+class FakeLogger:
     def debug(self, msg):
         pass
 

test/test_execution.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 import unittest
 
 import sys
@@ -45,7 +41,7 @@ def test_lazy_extractors(self):
         finally:
             try:
                 os.remove('yt_dlp/extractor/lazy_extractors.py')
-            except (IOError, OSError):
+            except OSError:
                 pass
 
 

test/test_http.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -41,7 +38,7 @@ def do_GET(self):
             assert False
 
 
-class FakeLogger(object):
+class FakeLogger:
     def debug(self, msg):
         pass
 
@@ -117,23 +114,23 @@ def setUp(self):
         self.geo_proxy_thread.start()
 
     def test_proxy(self):
-        geo_proxy = '127.0.0.1:{0}'.format(self.geo_port)
+        geo_proxy = f'127.0.0.1:{self.geo_port}'
         ydl = YoutubeDL({
-            'proxy': '127.0.0.1:{0}'.format(self.port),
+            'proxy': f'127.0.0.1:{self.port}',
             'geo_verification_proxy': geo_proxy,
         })
         url = 'http://foo.com/bar'
         response = ydl.urlopen(url).read().decode('utf-8')
-        self.assertEqual(response, 'normal: {0}'.format(url))
+        self.assertEqual(response, f'normal: {url}')
 
         req = compat_urllib_request.Request(url)
         req.add_header('Ytdl-request-proxy', geo_proxy)
         response = ydl.urlopen(req).read().decode('utf-8')
-        self.assertEqual(response, 'geo: {0}'.format(url))
+        self.assertEqual(response, f'geo: {url}')
 
     def test_proxy_with_idn(self):
         ydl = YoutubeDL({
-            'proxy': '127.0.0.1:{0}'.format(self.port),
+            'proxy': f'127.0.0.1:{self.port}',
         })
         url = 'http://中文.tw/'
         response = ydl.urlopen(url).read().decode('utf-8')

test/test_iqiyi_sdk_interpreter.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -12,7 +9,7 @@
 from yt_dlp.extractor import IqiyiIE
 
 
-class WarningLogger(object):
+class WarningLogger:
     def __init__(self):
         self.messages = []
 

test/test_jsinterp.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_netrc.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import os
 import sys
 import unittest

test/test_overwrites.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 import os
 from os.path import join
 import subprocess

test/test_post_hooks.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 import os
 import sys
 import unittest
@@ -14,7 +11,7 @@
 
 class YoutubeDL(yt_dlp.YoutubeDL):
     def __init__(self, *args, **kwargs):
-        super(YoutubeDL, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.to_stderr = self.to_screen
 
 

test/test_postprocessors.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_socks.py

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_subtitles.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -54,7 +52,7 @@ def getSubtitles(self):
             if sub_info.get('data') is None:
                 uf = self.DL.urlopen(sub_info['url'])
                 sub_info['data'] = uf.read().decode('utf-8')
-        return dict((l, sub_info['data']) for l, sub_info in subtitles.items())
+        return {l: sub_info['data'] for l, sub_info in subtitles.items()}
 
 
 @is_download_test
@@ -163,7 +161,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['de', 'en', 'es', 'fr']))
+        self.assertEqual(set(subtitles.keys()), {'de', 'en', 'es', 'fr'})
         self.assertEqual(md5(subtitles['en']), '8062383cf4dec168fc40a088aa6d5888')
         self.assertEqual(md5(subtitles['fr']), 'b6191146a6c5d3a452244d853fde6dc8')
 
@@ -186,7 +184,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['heb']))
+        self.assertEqual(set(subtitles.keys()), {'heb'})
         self.assertEqual(md5(subtitles['heb']), 'e758c5d7cb982f6bef14f377ec7a3920')
 
     def test_nosubtitles(self):
@@ -208,7 +206,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['cs']))
+        self.assertEqual(set(subtitles.keys()), {'cs'})
         self.assertTrue(len(subtitles['cs']) > 20000)
 
     def test_nosubtitles(self):
@@ -229,7 +227,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), '09bbe67222259bed60deaa26997d73a7')
 
 
@@ -242,7 +240,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['nl']))
+        self.assertEqual(set(subtitles.keys()), {'nl'})
         self.assertEqual(md5(subtitles['nl']), 'fc6435027572b63fb4ab143abd5ad3f4')
 
 
@@ -252,13 +250,13 @@ class TestMTVSubtitles(BaseTestSubtitles):
     IE = ComedyCentralIE
 
     def getInfoDict(self):
-        return super(TestMTVSubtitles, self).getInfoDict()['entries'][0]
+        return super().getInfoDict()['entries'][0]
 
     def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), '78206b8d8a0cfa9da64dc026eea48961')
 
 
@@ -271,7 +269,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['no']))
+        self.assertEqual(set(subtitles.keys()), {'no'})
         self.assertEqual(md5(subtitles['no']), '544fa917d3197fcbee64634559221cc2')
 
 
@@ -284,7 +282,7 @@ def test_subtitles_key(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['it']))
+        self.assertEqual(set(subtitles.keys()), {'it'})
         self.assertEqual(md5(subtitles['it']), 'b1d90a98755126b61e667567a1f6680a')
 
     def test_subtitles_array_key(self):
@@ -292,7 +290,7 @@ def test_subtitles_array_key(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['it']))
+        self.assertEqual(set(subtitles.keys()), {'it'})
         self.assertEqual(md5(subtitles['it']), '4b3264186fbb103508abe5311cfcb9cd')
 
 
@@ -305,7 +303,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), '53cb083a5914b2d84ef1ab67b880d18a')
 
 
@@ -320,7 +318,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), '97e7670cbae3c4d26ae8bcc7fdd78d4b')
 
 
@@ -333,7 +331,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), '48649a22e82b2da21c9a67a395eedade')
 
 
@@ -348,7 +346,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['es']))
+        self.assertEqual(set(subtitles.keys()), {'es'})
         self.assertEqual(md5(subtitles['es']), '69e70cae2d40574fb7316f31d6eb7fca')
 
 
@@ -361,7 +359,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), 'acaca989e24a9e45a6719c9b3d60815c')
 
     def test_subtitles_in_page(self):
@@ -369,7 +367,7 @@ def test_subtitles_in_page(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
         self.assertEqual(md5(subtitles['en']), 'acaca989e24a9e45a6719c9b3d60815c')
 
 
@@ -382,7 +380,7 @@ def test_allsubtitles(self):
         self.DL.params['writesubtitles'] = True
         self.DL.params['allsubtitles'] = True
         subtitles = self.getSubtitles()
-        self.assertEqual(set(subtitles.keys()), set(['en']))
+        self.assertEqual(set(subtitles.keys()), {'en'})
 
     def test_subtitles_dfxp_format(self):
         self.DL.params['writesubtitles'] = True

test/test_update.py.disabled

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_utils.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -266,7 +262,7 @@ def test_extract_basic_auth(self):
 
     def test_expand_path(self):
         def env(var):
-            return '%{0}%'.format(var) if sys.platform == 'win32' else '${0}'.format(var)
+            return f'%{var}%' if sys.platform == 'win32' else f'${var}'
 
         compat_setenv('yt_dlp_EXPATH_PATH', 'expanded')
         self.assertEqual(expand_path(env('yt_dlp_EXPATH_PATH')), 'expanded')
@@ -666,8 +662,7 @@ def testPL(size, pagesize, sliceargs, expected):
             def get_page(pagenum):
                 firstid = pagenum * pagesize
                 upto = min(size, pagenum * pagesize + pagesize)
-                for i in range(firstid, upto):
+                yield from range(firstid, upto)
-                    yield i
 
             pl = OnDemandPagedList(get_page, pagesize)
             got = pl.getslice(*sliceargs)
@@ -736,7 +731,7 @@ def test_multipart_encode(self):
             multipart_encode({b'field': b'value'}, boundary='AAAAAA')[0],
             b'--AAAAAA\r\nContent-Disposition: form-data; name="field"\r\n\r\nvalue\r\n--AAAAAA--\r\n')
         self.assertEqual(
-            multipart_encode({'欄位'.encode('utf-8'): '值'.encode('utf-8')}, boundary='AAAAAA')[0],
+            multipart_encode({'欄位'.encode(): '值'.encode()}, boundary='AAAAAA')[0],
             b'--AAAAAA\r\nContent-Disposition: form-data; name="\xe6\xac\x84\xe4\xbd\x8d"\r\n\r\n\xe5\x80\xbc\r\n--AAAAAA--\r\n')
         self.assertRaises(
             ValueError, multipart_encode, {b'field': b'value'}, boundary='value')
@@ -1397,7 +1392,7 @@ def test_dfxp2srt(self):
                     <p begin="3" dur="-1">Ignored, three</p>
                 </div>
             </body>
-            </tt>'''.encode('utf-8')
+            </tt>'''.encode()
         srt_data = '''1
 00:00:00,000 --> 00:00:01,000
 The following line contains Chinese characters and special symbols
@@ -1415,14 +1410,14 @@ def test_dfxp2srt(self):
 '''
         self.assertEqual(dfxp2srt(dfxp_data), srt_data)
 
-        dfxp_data_no_default_namespace = '''<?xml version="1.0" encoding="UTF-8"?>
+        dfxp_data_no_default_namespace = b'''<?xml version="1.0" encoding="UTF-8"?>
             <tt xml:lang="en" xmlns:tts="http://www.w3.org/ns/ttml#parameter">
             <body>
                 <div xml:lang="en">
                     <p begin="0" end="1">The first line</p>
                 </div>
             </body>
-            </tt>'''.encode('utf-8')
+            </tt>'''
         srt_data = '''1
 00:00:00,000 --> 00:00:01,000
 The first line
@@ -1430,7 +1425,7 @@ def test_dfxp2srt(self):
 '''
         self.assertEqual(dfxp2srt(dfxp_data_no_default_namespace), srt_data)
 
-        dfxp_data_with_style = '''<?xml version="1.0" encoding="utf-8"?>
+        dfxp_data_with_style = b'''<?xml version="1.0" encoding="utf-8"?>
 <tt xmlns="http://www.w3.org/2006/10/ttaf1" xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter" ttp:timeBase="media" xmlns:tts="http://www.w3.org/2006/10/ttaf1#style" xml:lang="en" xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
   <head>
     <styling>
@@ -1448,7 +1443,7 @@ def test_dfxp2srt(self):
       <p style="s1" tts:textDecoration="underline" begin="00:00:09.56" id="p2" end="00:00:12.36"><span style="s2" tts:color="lime">inner<br /> </span>style</p>
     </div>
   </body>
-</tt>'''.encode('utf-8')
+</tt>'''
         srt_data = '''1
 00:00:02,080 --> 00:00:05,840
 <font color="white" face="sansSerif" size="16">default style<font color="red">custom style</font></font>

test/test_verbose_output.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 import unittest
 
 import sys

test/test_write_annotations.py.disabled

@@ -1,7 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
@@ -21,7 +18,7 @@ import yt_dlp.extractor
 
 class YoutubeDL(yt_dlp.YoutubeDL):
     def __init__(self, *args, **kwargs):
-        super(YoutubeDL, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.to_stderr = self.to_screen
 
 
@@ -52,7 +49,7 @@ class TestAnnotations(unittest.TestCase):
         ydl.download([TEST_ID])
         self.assertTrue(os.path.exists(ANNOTATIONS_FILE))
         annoxml = None
-        with io.open(ANNOTATIONS_FILE, 'r', encoding='utf-8') as annof:
+        with open(ANNOTATIONS_FILE, encoding='utf-8') as annof:
             annoxml = xml.etree.ElementTree.parse(annof)
         self.assertTrue(annoxml is not None, 'Failed to parse annotations XML')
         root = annoxml.getroot()

test/test_youtube_lists.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_youtube_misc.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys

test/test_youtube_signature.py

@@ -1,14 +1,10 @@
 #!/usr/bin/env python3
-
-from __future__ import unicode_literals
-
 # Allow direct execution
 import os
 import sys
 import unittest
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
-import io
 import re
 import string
 import urllib.request
@@ -149,7 +145,7 @@ def test_func(self):
 
             if not os.path.exists(fn):
                 urllib.request.urlretrieve(url, fn)
-            with io.open(fn, encoding='utf-8') as testf:
+            with open(fn, encoding='utf-8') as testf:
                 jscode = testf.read()
             self.assertEqual(sig_func(jscode, sig_input), expected_sig)
 

yt_dlp/YoutubeDL.py

@@ -1,8 +1,4 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
-from __future__ import absolute_import, unicode_literals
-
 import collections
 import contextlib
 import datetime
@@ -165,7 +161,7 @@
     import ctypes
 
 
-class YoutubeDL(object):
+class YoutubeDL:
     """YoutubeDL class.
 
     YoutubeDL objects are the ones responsible of downloading the
@@ -501,7 +497,7 @@ class YoutubeDL(object):
                        care about HLS. (only for youtube)
     """
 
-    _NUMERIC_FIELDS = set((
+    _NUMERIC_FIELDS = {
         'width', 'height', 'tbr', 'abr', 'asr', 'vbr', 'fps', 'filesize', 'filesize_approx',
         'timestamp', 'release_timestamp',
         'duration', 'view_count', 'like_count', 'dislike_count', 'repost_count',
@@ -509,7 +505,7 @@ class YoutubeDL(object):
         'start_time', 'end_time',
         'chapter_number', 'season_number', 'episode_number',
         'track_number', 'disc_number', 'release_year',
-    ))
+    }
 
     _format_fields = {
         # NB: Keep in sync with the docstring of extractor/common.py
@@ -576,7 +572,7 @@ def __init__(self, params=None, auto_init=True):
 
         def check_deprecated(param, option, suggestion):
             if self.params.get(param) is not None:
-                self.report_warning('%s is deprecated. Use %s instead' % (option, suggestion))
+                self.report_warning(f'{option} is deprecated. Use {suggestion} instead')
                 return True
             return False
 
@@ -693,7 +689,7 @@ def preload_download_archive(fn):
                 with locked_file(fn, 'r', encoding='utf-8') as archive_file:
                     for line in archive_file:
                         self.archive.add(line.strip())
-            except IOError as ioe:
+            except OSError as ioe:
                 if ioe.errno != errno.ENOENT:
                     raise
                 return False
@@ -990,11 +986,9 @@ def parse_outtmpl(self):
         outtmpl_dict.update({
             k: sanitize(v) for k, v in DEFAULT_OUTTMPL.items()
             if outtmpl_dict.get(k) is None})
-        for key, val in outtmpl_dict.items():
+        for _, val in outtmpl_dict.items():
             if isinstance(val, bytes):
-                self.report_warning(
+                self.report_warning('Parameter outtmpl is bytes, but should be a unicode string')
-                    'Parameter outtmpl is bytes, but should be a unicode string. '
-                    'Put  from __future__ import unicode_literals  at the top of your code file or consider switching to Python 3.x.')
         return outtmpl_dict
 
     def get_output_path(self, dir_type='', filename=None):
@@ -1013,7 +1007,7 @@ def _outtmpl_expandpath(outtmpl):
         # '%%' intact for template dict substitution step. Working around
         # with boundary-alike separator hack.
         sep = ''.join([random.choice(ascii_letters) for _ in range(32)])
-        outtmpl = outtmpl.replace('%%', '%{0}%'.format(sep)).replace('$$', '${0}$'.format(sep))
+        outtmpl = outtmpl.replace('%%', f'%{sep}%').replace('$$', f'${sep}$')
 
         # outtmpl should be expand_path'ed before template dict substitution
         # because meta fields may contain env variables we don't want to
@@ -1173,7 +1167,7 @@ def create_key(outer_mobj):
 
             fmt = outer_mobj.group('format')
             if fmt == 's' and value is not None and key in field_size_compat_map.keys():
-                fmt = '0{:d}d'.format(field_size_compat_map[key])
+                fmt = f'0{field_size_compat_map[key]:d}d'
 
             value = default if value is None else value if replacement is None else replacement
 
@@ -1188,7 +1182,7 @@ def create_key(outer_mobj):
                 value = map(str, variadic(value) if '#' in flags else [value])
                 value, fmt = ' '.join(map(compat_shlex_quote, value)), str_fmt
             elif fmt[-1] == 'B':  # bytes
-                value = f'%{str_fmt}'.encode('utf-8') % str(value).encode('utf-8')
+                value = f'%{str_fmt}'.encode() % str(value).encode('utf-8')
                 value, fmt = value.decode('utf-8', 'ignore'), 's'
             elif fmt[-1] == 'U':  # unicode normalized
                 value, fmt = unicodedata.normalize(
@@ -1301,7 +1295,7 @@ def check_filter():
             if date is not None:
                 dateRange = self.params.get('daterange', DateRange())
                 if date not in dateRange:
-                    return '%s upload date is not in range %s' % (date_from_str(date).isoformat(), dateRange)
+                    return f'{date_from_str(date).isoformat()} upload date is not in range {dateRange}'
             view_count = info_dict.get('view_count')
             if view_count is not None:
                 min_views = self.params.get('min_views')
@@ -1765,14 +1759,14 @@ def get_entry(i):
 
         x_forwarded_for = ie_result.get('__x_forwarded_for_ip')
 
-        self.to_screen('[%s] playlist %s: %s' % (ie_result['extractor'], playlist, msg % n_entries))
+        self.to_screen(f'[{ie_result["extractor"]}] playlist {playlist}: {msg % n_entries}')
         failures = 0
         max_failures = self.params.get('skip_playlist_after_errors') or float('inf')
         for i, entry_tuple in enumerate(entries, 1):
             playlist_index, entry = entry_tuple
             if 'playlist-index' in self.params.get('compat_opts', []):
                 playlist_index = playlistitems[i - 1] if playlistitems else i + playliststart - 1
-            self.to_screen('[download] Downloading video %s of %s' % (i, n_entries))
+            self.to_screen(f'[download] Downloading video {i} of {n_entries}')
             # This __x_forwarded_for_ip thing is a bit ugly but requires
             # minimal changes
             if x_forwarded_for:
@@ -1940,7 +1934,7 @@ def build_format_selector(self, format_spec):
         def syntax_error(note, start):
             message = (
                 'Invalid format specification: '
-                '{0}\n\t{1}\n\t{2}^'.format(note, format_spec, ' ' * start[1]))
+                '{}\n\t{}\n\t{}^'.format(note, format_spec, ' ' * start[1]))
             return SyntaxError(message)
 
         PICKFIRST = 'PICKFIRST'
@@ -2044,7 +2038,7 @@ def _parse_format_selection(tokens, inside_merge=False, inside_choice=False, ins
                             raise syntax_error('Expected a selector', start)
                         current_selector = FormatSelector(MERGE, (selector_1, selector_2), [])
                     else:
-                        raise syntax_error('Operator not recognized: "{0}"'.format(string), start)
+                        raise syntax_error(f'Operator not recognized: "{string}"', start)
                 elif type == tokenize.ENDMARKER:
                     break
             if current_selector:
@@ -2244,7 +2238,7 @@ def final_selector(ctx):
         except tokenize.TokenError:
             raise syntax_error('Missing closing/opening brackets or parenthesis', (0, len(format_spec)))
 
-        class TokenIterator(object):
+        class TokenIterator:
             def __init__(self, tokens):
                 self.tokens = tokens
                 self.counter = 0
@@ -2644,7 +2638,7 @@ def is_wellformed(f):
                 if max_downloads_reached:
                     break
 
-            write_archive = set(f.get('__write_download_archive', False) for f in formats_to_download)
+            write_archive = {f.get('__write_download_archive', False) for f in formats_to_download}
             assert write_archive.issubset({True, False, 'ignore'})
             if True in write_archive and False not in write_archive:
                 self.record_download_archive(info_dict)
@@ -2712,7 +2706,7 @@ def process_subtitles(self, video_id, normal_subtitles, automatic_captions):
         for lang in requested_langs:
             formats = available_subs.get(lang)
             if formats is None:
-                self.report_warning('%s subtitles not available for %s' % (lang, video_id))
+                self.report_warning(f'{lang} subtitles not available for {video_id}')
                 continue
             for ext in formats_preference:
                 if ext == 'best':
@@ -2755,7 +2749,7 @@ def format_tmpl(tmpl):
             tmpl = format_tmpl(tmpl)
             self.to_screen(f'[info] Writing {tmpl!r} to: {filename}')
             if self._ensure_dir_exists(filename):
-                with io.open(filename, 'a', encoding='utf-8') as f:
+                with open(filename, 'a', encoding='utf-8') as f:
                     f.write(self.evaluate_outtmpl(tmpl, info_copy) + '\n')
 
     def __forced_printings(self, info_dict, filename, incomplete):
@@ -2920,11 +2914,11 @@ def process_info(self, info_dict):
             else:
                 try:
                     self.to_screen('[info] Writing video annotations to: ' + annofn)
-                    with io.open(encodeFilename(annofn), 'w', encoding='utf-8') as annofile:
+                    with open(encodeFilename(annofn), 'w', encoding='utf-8') as annofile:
                         annofile.write(info_dict['annotations'])
                 except (KeyError, TypeError):
                     self.report_warning('There are no annotations to write.')
-                except (OSError, IOError):
+                except OSError:
                     self.report_error('Cannot write annotations file: ' + annofn)
                     return
 
@@ -2943,13 +2937,13 @@ def _write_link_file(link_type):
                 return True
             try:
                 self.to_screen(f'[info] Writing internet shortcut (.{link_type}) to: {linkfn}')
-                with io.open(encodeFilename(to_high_limit_path(linkfn)), 'w', encoding='utf-8',
+                with open(encodeFilename(to_high_limit_path(linkfn)), 'w', encoding='utf-8',
-                             newline='\r\n' if link_type == 'url' else '\n') as linkfile:
+                          newline='\r\n' if link_type == 'url' else '\n') as linkfile:
                     template_vars = {'url': url}
                     if link_type == 'desktop':
                         template_vars['filename'] = linkfn[:-(len(link_type) + 1)]
                     linkfile.write(LINK_TEMPLATES[link_type] % template_vars)
-            except (OSError, IOError):
+            except OSError:
                 self.report_error(f'Cannot write internet shortcut {linkfn}')
                 return False
             return True
@@ -3014,10 +3008,10 @@ def compatible_formats(formats):
                             return False
 
                         # Check extension
-                        exts = set(format.get('ext') for format in formats)
+                        exts = {format.get('ext') for format in formats}
                         COMPATIBLE_EXTS = (
-                            set(('mp3', 'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'ismv', 'isma')),
+                            {'mp3', 'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'ismv', 'isma'},
-                            set(('webm',)),
+                            {'webm'},
                         )
                         for ext_sets in COMPATIBLE_EXTS:
                             if ext_sets.issuperset(exts):
@@ -3050,7 +3044,7 @@ def correct_ext(filename, ext=new_ext):
                             os.path.splitext(filename)[0]
                             if filename_real_ext in (old_ext, new_ext)
                             else filename)
-                        return '%s.%s' % (filename_wo_ext, ext)
+                        return f'{filename_wo_ext}.{ext}'
 
                     # Ensure filename always has a correct extension for successful merge
                     full_filename = correct_ext(full_filename)
@@ -3135,10 +3129,10 @@ def correct_ext(filename, ext=new_ext):
             except network_exceptions as err:
                 self.report_error('unable to download video data: %s' % error_to_compat_str(err))
                 return
-            except (OSError, IOError) as err:
+            except OSError as err:
                 raise UnavailableVideoError(err)
             except (ContentTooShortError, ) as err:
-                self.report_error('content too short (expected %s bytes and served %s)' % (err.expected, err.downloaded))
+                self.report_error(f'content too short (expected {err.expected} bytes and served {err.downloaded})')
                 return
 
             if success and full_filename != '-':
@@ -3343,7 +3337,7 @@ def run_pp(self, pp, infodict):
                 self.to_screen('Deleting original file %s (pass -k to keep)' % old_filename)
                 try:
                     os.remove(encodeFilename(old_filename))
-                except (IOError, OSError):
+                except OSError:
                     self.report_warning('Unable to remove downloaded original file')
                 if old_filename in infodict['__files_to_move']:
                     del infodict['__files_to_move'][old_filename]
@@ -3388,7 +3382,7 @@ def _make_archive_id(self, info_dict):
                     break
             else:
                 return
-        return '%s %s' % (extractor.lower(), video_id)
+        return f'{extractor.lower()} {video_id}'
 
     def in_download_archive(self, info_dict):
         fn = self.params.get('download_archive')
@@ -3791,7 +3785,7 @@ def _write_info_json(self, label, ie_result, infofn, overwrite=None):
         try:
             write_json_file(self.sanitize_info(ie_result, self.params.get('clean_infojson', True)), infofn)
             return True
-        except (OSError, IOError):
+        except OSError:
             self.report_error(f'Cannot write {label} metadata to JSON file {infofn}')
             return None
 
@@ -3812,9 +3806,9 @@ def _write_description(self, label, ie_result, descfn):
         else:
             try:
                 self.to_screen(f'[info] Writing {label} description to: {descfn}')
-                with io.open(encodeFilename(descfn), 'w', encoding='utf-8') as descfile:
+                with open(encodeFilename(descfn), 'w', encoding='utf-8') as descfile:
                     descfile.write(ie_result['description'])
-            except (OSError, IOError):
+            except OSError:
                 self.report_error(f'Cannot write {label} description file {descfn}')
                 return None
         return True
@@ -3848,12 +3842,12 @@ def _write_subtitles(self, info_dict, filename):
                 try:
                     # Use newline='' to prevent conversion of newline characters
                     # See https://github.com/ytdl-org/youtube-dl/issues/10268
-                    with io.open(sub_filename, 'w', encoding='utf-8', newline='') as subfile:
+                    with open(sub_filename, 'w', encoding='utf-8', newline='') as subfile:
                         subfile.write(sub_info['data'])
                     sub_info['filepath'] = sub_filename
                     ret.append((sub_filename, sub_filename_final))
                     continue
-                except (OSError, IOError):
+                except OSError:
                     self.report_error(f'Cannot write video subtitles file {sub_filename}')
                     return None
 

yt_dlp/__init__.py

@@ -1,11 +1,8 @@
 #!/usr/bin/env python3
-# coding: utf-8
-
 f'You are using an unsupported version of Python. Only Python versions 3.6 and above are supported by yt-dlp'  # noqa: F541
 
 __license__ = 'Public Domain'
 
-import io
 import itertools
 import os
 import random
@@ -67,13 +64,12 @@ def get_urls(urls, batchfile, verbose):
                     'Ctrl+Z' if compat_os_name == 'nt' else 'Ctrl+D'))
                 batchfd = sys.stdin
             else:
-                batchfd = io.open(
+                batchfd = open(
-                    expand_path(batchfile),
+                    expand_path(batchfile), encoding='utf-8', errors='ignore')
-                    'r', encoding='utf-8', errors='ignore')
             batch_urls = read_batch_urls(batchfd)
             if verbose:
                 write_string('[debug] Batch file urls: ' + repr(batch_urls) + '\n')
-        except IOError:
+        except OSError:
             sys.exit('ERROR: batch file %s could not be read' % batchfile)
     _enc = preferredencoding()
     return [

yt_dlp/__main__.py

@@ -1,6 +1,4 @@
 #!/usr/bin/env python3
-from __future__ import unicode_literals
-
 # Execute with
 # $ python -m yt_dlp
 

yt_dlp/aes.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from math import ceil
 
 from .compat import (

yt_dlp/cache.py

@@ -1,7 +1,4 @@
-from __future__ import unicode_literals
-
 import errno
-import io
 import json
 import os
 import re
@@ -15,7 +12,7 @@
 )
 
 
-class Cache(object):
+class Cache:
     def __init__(self, ydl):
         self._ydl = ydl
 
@@ -31,7 +28,7 @@ def _get_cache_fn(self, section, key, dtype):
             'invalid section %r' % section
         assert re.match(r'^[a-zA-Z0-9_.-]+$', key), 'invalid key %r' % key
         return os.path.join(
-            self._get_root_dir(), section, '%s.%s' % (key, dtype))
+            self._get_root_dir(), section, f'{key}.{dtype}')
 
     @property
     def enabled(self):
@@ -54,8 +51,7 @@ def store(self, section, key, data, dtype='json'):
             write_json_file(data, fn)
         except Exception:
             tb = traceback.format_exc()
-            self._ydl.report_warning(
+            self._ydl.report_warning(f'Writing cache to {fn!r} failed: {tb}')
-                'Writing cache to %r failed: %s' % (fn, tb))
 
     def load(self, section, key, dtype='json', default=None):
         assert dtype in ('json',)
@@ -66,17 +62,16 @@ def load(self, section, key, dtype='json', default=None):
         cache_fn = self._get_cache_fn(section, key, dtype)
         try:
             try:
-                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
+                with open(cache_fn, encoding='utf-8') as cachef:
                     self._ydl.write_debug(f'Loading {section}.{key} from cache')
                     return json.load(cachef)
             except ValueError:
                 try:
                     file_size = os.path.getsize(cache_fn)
-                except (OSError, IOError) as oe:
+                except OSError as oe:
                     file_size = str(oe)
-                self._ydl.report_warning(
+                self._ydl.report_warning(f'Cache retrieval from {cache_fn} failed ({file_size})')
-                    'Cache retrieval from %s failed (%s)' % (cache_fn, file_size))
+        except OSError:
-        except IOError:
             pass  # No cache available
 
         return default

yt_dlp/compat.py

@@ -1,5 +1,3 @@
-# coding: utf-8
-
 import asyncio
 import base64
 import collections

yt_dlp/cookies.py

@@ -125,7 +125,7 @@ def extract_cookies_from_browser(browser_name, profile=None, logger=YDLLogger(),
     elif browser_name in CHROMIUM_BASED_BROWSERS:
         return _extract_chrome_cookies(browser_name, profile, keyring, logger)
     else:
-        raise ValueError('unknown browser: {}'.format(browser_name))
+        raise ValueError(f'unknown browser: {browser_name}')
 
 
 def _extract_firefox_cookies(profile, logger):
@@ -144,8 +144,8 @@ def _extract_firefox_cookies(profile, logger):
 
     cookie_database_path = _find_most_recently_used_file(search_root, 'cookies.sqlite', logger)
     if cookie_database_path is None:
-        raise FileNotFoundError('could not find firefox cookies database in {}'.format(search_root))
+        raise FileNotFoundError(f'could not find firefox cookies database in {search_root}')
-    logger.debug('Extracting cookies from: "{}"'.format(cookie_database_path))
+    logger.debug(f'Extracting cookies from: "{cookie_database_path}"')
 
     with tempfile.TemporaryDirectory(prefix='yt_dlp') as tmpdir:
         cursor = None
@@ -164,7 +164,7 @@ def _extract_firefox_cookies(profile, logger):
                         path=path, path_specified=bool(path), secure=is_secure, expires=expiry, discard=False,
                         comment=None, comment_url=None, rest={})
                     jar.set_cookie(cookie)
-            logger.info('Extracted {} cookies from firefox'.format(len(jar)))
+            logger.info(f'Extracted {len(jar)} cookies from firefox')
             return jar
         finally:
             if cursor is not None:
@@ -179,7 +179,7 @@ def _firefox_browser_dir():
     elif sys.platform == 'darwin':
         return os.path.expanduser('~/Library/Application Support/Firefox')
     else:
-        raise ValueError('unsupported platform: {}'.format(sys.platform))
+        raise ValueError(f'unsupported platform: {sys.platform}')
 
 
 def _get_chromium_based_browser_settings(browser_name):
@@ -219,7 +219,7 @@ def _get_chromium_based_browser_settings(browser_name):
         }[browser_name]
 
     else:
-        raise ValueError('unsupported platform: {}'.format(sys.platform))
+        raise ValueError(f'unsupported platform: {sys.platform}')
 
     # Linux keyring names can be determined by snooping on dbus while opening the browser in KDE:
     # dbus-monitor "interface='org.kde.KWallet'" "type=method_return"
@@ -242,7 +242,7 @@ def _get_chromium_based_browser_settings(browser_name):
 
 
 def _extract_chrome_cookies(browser_name, profile, keyring, logger):
-    logger.info('Extracting cookies from {}'.format(browser_name))
+    logger.info(f'Extracting cookies from {browser_name}')
 
     if not SQLITE_AVAILABLE:
         logger.warning(('Cannot extract cookies from {} without sqlite3 support. '
@@ -260,13 +260,13 @@ def _extract_chrome_cookies(browser_name, profile, keyring, logger):
         if config['supports_profiles']:
             search_root = os.path.join(config['browser_dir'], profile)
         else:
-            logger.error('{} does not support profiles'.format(browser_name))
+            logger.error(f'{browser_name} does not support profiles')
             search_root = config['browser_dir']
 
     cookie_database_path = _find_most_recently_used_file(search_root, 'Cookies', logger)
     if cookie_database_path is None:
-        raise FileNotFoundError('could not find {} cookies database in "{}"'.format(browser_name, search_root))
+        raise FileNotFoundError(f'could not find {browser_name} cookies database in "{search_root}"')
-    logger.debug('Extracting cookies from: "{}"'.format(cookie_database_path))
+    logger.debug(f'Extracting cookies from: "{cookie_database_path}"')
 
     decryptor = get_cookie_decryptor(config['browser_dir'], config['keyring_name'], logger, keyring=keyring)
 
@@ -295,13 +295,13 @@ def _extract_chrome_cookies(browser_name, profile, keyring, logger):
                         unencrypted_cookies += 1
                     jar.set_cookie(cookie)
             if failed_cookies > 0:
-                failed_message = ' ({} could not be decrypted)'.format(failed_cookies)
+                failed_message = f' ({failed_cookies} could not be decrypted)'
             else:
                 failed_message = ''
-            logger.info('Extracted {} cookies from {}{}'.format(len(jar), browser_name, failed_message))
+            logger.info(f'Extracted {len(jar)} cookies from {browser_name}{failed_message}')
             counts = decryptor.cookie_counts.copy()
             counts['unencrypted'] = unencrypted_cookies
-            logger.debug('cookie version breakdown: {}'.format(counts))
+            logger.debug(f'cookie version breakdown: {counts}')
             return jar
         finally:
             if cursor is not None:
@@ -492,7 +492,7 @@ def _extract_safari_cookies(profile, logger):
     if profile is not None:
         logger.error('safari does not support profiles')
     if sys.platform != 'darwin':
-        raise ValueError('unsupported platform: {}'.format(sys.platform))
+        raise ValueError(f'unsupported platform: {sys.platform}')
 
     cookies_path = os.path.expanduser('~/Library/Cookies/Cookies.binarycookies')
 
@@ -506,7 +506,7 @@ def _extract_safari_cookies(profile, logger):
         cookies_data = f.read()
 
     jar = parse_safari_cookies(cookies_data, logger=logger)
-    logger.info('Extracted {} cookies from safari'.format(len(jar)))
+    logger.info(f'Extracted {len(jar)} cookies from safari')
     return jar
 
 
@@ -522,7 +522,7 @@ def __init__(self, data, logger):
 
     def read_bytes(self, num_bytes):
         if num_bytes < 0:
-            raise ParserError('invalid read of {} bytes'.format(num_bytes))
+            raise ParserError(f'invalid read of {num_bytes} bytes')
         end = self.cursor + num_bytes
         if end > len(self._data):
             raise ParserError('reached end of input')
@@ -533,7 +533,7 @@ def read_bytes(self, num_bytes):
     def expect_bytes(self, expected_value, message):
         value = self.read_bytes(len(expected_value))
         if value != expected_value:
-            raise ParserError('unexpected value: {} != {} ({})'.format(value, expected_value, message))
+            raise ParserError(f'unexpected value: {value} != {expected_value} ({message})')
 
     def read_uint(self, big_endian=False):
         data_format = '>I' if big_endian else '<I'
@@ -557,7 +557,7 @@ def skip(self, num_bytes, description='unknown'):
             self._logger.debug('skipping {} bytes ({}): {}'.format(
                 num_bytes, description, self.read_bytes(num_bytes)))
         elif num_bytes < 0:
-            raise ParserError('invalid skip of {} bytes'.format(num_bytes))
+            raise ParserError(f'invalid skip of {num_bytes} bytes')
 
     def skip_to(self, offset, description='unknown'):
         self.skip(offset - self.cursor, description)
@@ -584,7 +584,7 @@ def _parse_safari_cookies_page(data, jar, logger):
     number_of_cookies = p.read_uint()
     record_offsets = [p.read_uint() for _ in range(number_of_cookies)]
     if number_of_cookies == 0:
-        logger.debug('a cookies page of size {} has no cookies'.format(len(data)))
+        logger.debug(f'a cookies page of size {len(data)} has no cookies')
         return
 
     p.skip_to(record_offsets[0], 'unknown page header field')
@@ -730,7 +730,7 @@ def _choose_linux_keyring(logger):
     SelectBackend
     """
     desktop_environment = _get_linux_desktop_environment(os.environ)
-    logger.debug('detected desktop environment: {}'.format(desktop_environment.name))
+    logger.debug(f'detected desktop environment: {desktop_environment.name}')
     if desktop_environment == _LinuxDesktopEnvironment.KDE:
         linux_keyring = _LinuxKeyring.KWALLET
     elif desktop_environment == _LinuxDesktopEnvironment.OTHER:
@@ -764,10 +764,10 @@ def _get_kwallet_network_wallet(logger):
             return default_wallet
         else:
             network_wallet = stdout.decode('utf-8').strip()
-            logger.debug('NetworkWallet = "{}"'.format(network_wallet))
+            logger.debug(f'NetworkWallet = "{network_wallet}"')
             return network_wallet
     except Exception as e:
-        logger.warning('exception while obtaining NetworkWallet: {}'.format(e))
+        logger.warning(f'exception while obtaining NetworkWallet: {e}')
         return default_wallet
 
 
@@ -785,8 +785,8 @@ def _get_kwallet_password(browser_keyring_name, logger):
     try:
         proc = Popen([
             'kwallet-query',
-            '--read-password', '{} Safe Storage'.format(browser_keyring_name),
+            '--read-password', f'{browser_keyring_name} Safe Storage',
-            '--folder', '{} Keys'.format(browser_keyring_name),
+            '--folder', f'{browser_keyring_name} Keys',
             network_wallet
         ], stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
 
@@ -818,7 +818,7 @@ def _get_kwallet_password(browser_keyring_name, logger):
 
 def _get_gnome_keyring_password(browser_keyring_name, logger):
     if not SECRETSTORAGE_AVAILABLE:
-        logger.error('secretstorage not available {}'.format(SECRETSTORAGE_UNAVAILABLE_REASON))
+        logger.error(f'secretstorage not available {SECRETSTORAGE_UNAVAILABLE_REASON}')
         return b''
     # the Gnome keyring does not seem to organise keys in the same way as KWallet,
     # using `dbus-monitor` during startup, it can be observed that chromium lists all keys
@@ -827,7 +827,7 @@ def _get_gnome_keyring_password(browser_keyring_name, logger):
     with contextlib.closing(secretstorage.dbus_init()) as con:
         col = secretstorage.get_default_collection(con)
         for item in col.get_all_items():
-            if item.get_label() == '{} Safe Storage'.format(browser_keyring_name):
+            if item.get_label() == f'{browser_keyring_name} Safe Storage':
                 return item.get_secret()
         else:
             logger.error('failed to read from keyring')
@@ -861,7 +861,7 @@ def _get_mac_keyring_password(browser_keyring_name, logger):
             ['security', 'find-generic-password',
              '-w',  # write password to stdout
              '-a', browser_keyring_name,  # match 'account'
-             '-s', '{} Safe Storage'.format(browser_keyring_name)],  # match 'service'
+             '-s', f'{browser_keyring_name} Safe Storage'],  # match 'service'
             stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
 
         stdout, stderr = proc.communicate_or_kill()
@@ -879,7 +879,7 @@ def _get_windows_v10_key(browser_root, logger):
         logger.error('could not find local state file')
         return None
     logger.debug(f'Found local state file at "{path}"')
-    with open(path, 'r', encoding='utf8') as f:
+    with open(path, encoding='utf8') as f:
         data = json.load(f)
     try:
         base64_key = data['os_crypt']['encrypted_key']
@@ -966,7 +966,7 @@ def _open_database_copy(database_path, tmpdir):
 
 
 def _get_column_names(cursor, table_name):
-    table_info = cursor.execute('PRAGMA table_info({})'.format(table_name)).fetchall()
+    table_info = cursor.execute(f'PRAGMA table_info({table_name})').fetchall()
     return [row[1].decode('utf-8') for row in table_info]
 
 

yt_dlp/downloader/__init__.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from ..compat import compat_str
 from ..utils import (
     determine_protocol,

yt_dlp/downloader/common.py

@@ -1,5 +1,3 @@
-from __future__ import division, unicode_literals
-
 import os
 import re
 import time
@@ -25,7 +23,7 @@
 )
 
 
-class FileDownloader(object):
+class FileDownloader:
     """File Downloader class.
 
     File downloader objects are the ones responsible of downloading the
@@ -219,7 +217,7 @@ def inner(self, *args, **kwargs):
                 while True:
                     try:
                         return func(self, *args, **kwargs)
-                    except (IOError, OSError) as err:
+                    except OSError as err:
                         retry = retry + 1
                         if retry > file_access_retries or err.errno not in (errno.EACCES, errno.EINVAL):
                             if not fatal:
@@ -486,4 +484,4 @@ def _debug_cmd(self, args, exe=None):
         if exe is None:
             exe = os.path.basename(str_args[0])
 
-        self.write_debug('%s command line: %s' % (exe, shell_quote(str_args)))
+        self.write_debug(f'{exe} command line: {shell_quote(str_args)}')

yt_dlp/downloader/dash.py

@@ -1,4 +1,3 @@
-from __future__ import unicode_literals
 import time
 
 from ..downloader import get_suitable_downloader
@@ -46,7 +45,7 @@ def real_download(self, filename, info_dict):
 
             if real_downloader:
                 self.to_screen(
-                    '[%s] Fragment downloads will be delegated to %s' % (self.FD_NAME, real_downloader.get_basename()))
+                    f'[{self.FD_NAME}] Fragment downloads will be delegated to {real_downloader.get_basename()}')
                 info_dict['fragments'] = list(fragments_to_download)
                 fd = real_downloader(self.ydl, self.params)
                 return fd.real_download(filename, info_dict)

yt_dlp/downloader/external.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import os.path
 import re
 import subprocess
@@ -56,7 +54,7 @@ def real_download(self, filename, info_dict):
             }
             if filename != '-':
                 fsize = os.path.getsize(encodeFilename(tmpfilename))
-                self.to_screen('\r[%s] Downloaded %s bytes' % (self.get_basename(), fsize))
+                self.to_screen(f'\r[{self.get_basename()}] Downloaded {fsize} bytes')
                 self.try_rename(tmpfilename, filename)
                 status.update({
                     'downloaded_bytes': fsize,
@@ -157,7 +155,7 @@ def _call_downloader(self, tmpfilename, info_dict):
             fragment_filename = '%s-Frag%d' % (tmpfilename, frag_index)
             try:
                 src, _ = self.sanitize_open(fragment_filename, 'rb')
-            except IOError as err:
+            except OSError as err:
                 if skip_unavailable_fragments and frag_index > 1:
                     self.report_skip_fragment(frag_index, err)
                     continue
@@ -179,7 +177,7 @@ def _make_cmd(self, tmpfilename, info_dict):
         cmd = [self.exe, '--location', '-o', tmpfilename, '--compressed']
         if info_dict.get('http_headers') is not None:
             for key, val in info_dict['http_headers'].items():
-                cmd += ['--header', '%s: %s' % (key, val)]
+                cmd += ['--header', f'{key}: {val}']
 
         cmd += self._bool_option('--continue-at', 'continuedl', '-', '0')
         cmd += self._valueless_option('--silent', 'noprogress')
@@ -216,7 +214,7 @@ def _make_cmd(self, tmpfilename, info_dict):
         cmd = [self.exe, '-o', tmpfilename]
         if info_dict.get('http_headers') is not None:
             for key, val in info_dict['http_headers'].items():
-                cmd += ['-H', '%s: %s' % (key, val)]
+                cmd += ['-H', f'{key}: {val}']
         cmd += self._configuration_args()
         cmd += ['--', info_dict['url']]
         return cmd
@@ -229,7 +227,7 @@ def _make_cmd(self, tmpfilename, info_dict):
         cmd = [self.exe, '-O', tmpfilename, '-nv', '--no-cookies', '--compression=auto']
         if info_dict.get('http_headers') is not None:
             for key, val in info_dict['http_headers'].items():
-                cmd += ['--header', '%s: %s' % (key, val)]
+                cmd += ['--header', f'{key}: {val}']
         cmd += self._option('--limit-rate', 'ratelimit')
         retry = self._option('--tries', 'retries')
         if len(retry) == 2:
@@ -240,7 +238,7 @@ def _make_cmd(self, tmpfilename, info_dict):
         proxy = self.params.get('proxy')
         if proxy:
             for var in ('http_proxy', 'https_proxy'):
-                cmd += ['--execute', '%s=%s' % (var, proxy)]
+                cmd += ['--execute', f'{var}={proxy}']
         cmd += self._valueless_option('--no-check-certificate', 'nocheckcertificate')
         cmd += self._configuration_args()
         cmd += ['--', info_dict['url']]
@@ -271,7 +269,7 @@ def _make_cmd(self, tmpfilename, info_dict):
 
         if info_dict.get('http_headers') is not None:
             for key, val in info_dict['http_headers'].items():
-                cmd += ['--header', '%s: %s' % (key, val)]
+                cmd += ['--header', f'{key}: {val}']
         cmd += self._option('--max-overall-download-limit', 'ratelimit')
         cmd += self._option('--interface', 'source_address')
         cmd += self._option('--all-proxy', 'proxy')
@@ -289,10 +287,10 @@ def _make_cmd(self, tmpfilename, info_dict):
         dn = os.path.dirname(tmpfilename)
         if dn:
             if not os.path.isabs(dn):
-                dn = '.%s%s' % (os.path.sep, dn)
+                dn = f'.{os.path.sep}{dn}'
             cmd += ['--dir', dn + os.path.sep]
         if 'fragments' not in info_dict:
-            cmd += ['--out', '.%s%s' % (os.path.sep, os.path.basename(tmpfilename))]
+            cmd += ['--out', f'.{os.path.sep}{os.path.basename(tmpfilename)}']
         cmd += ['--auto-file-renaming=false']
 
         if 'fragments' in info_dict:
@@ -320,7 +318,7 @@ def _make_cmd(self, tmpfilename, info_dict):
 
         if info_dict.get('http_headers') is not None:
             for key, val in info_dict['http_headers'].items():
-                cmd += ['%s:%s' % (key, val)]
+                cmd += [f'{key}:{val}']
         return cmd
 
 
@@ -393,7 +391,7 @@ def _call_downloader(self, tmpfilename, info_dict):
             headers = handle_youtubedl_headers(info_dict['http_headers'])
             args += [
                 '-headers',
-                ''.join('%s: %s\r\n' % (key, val) for key, val in headers.items())]
+                ''.join(f'{key}: {val}\r\n' for key, val in headers.items())]
 
         env = None
         proxy = self.params.get('proxy')

yt_dlp/downloader/f4m.py

@@ -1,5 +1,3 @@
-from __future__ import division, unicode_literals
-
 import io
 import itertools
 import time

yt_dlp/downloader/fc2.py

@@ -1,5 +1,3 @@
-from __future__ import division, unicode_literals
-
 import threading
 
 from .common import FileDownloader

yt_dlp/downloader/fragment.py

@@ -1,5 +1,3 @@
-from __future__ import division, unicode_literals
-
 import http.client
 import json
 import math
@@ -172,8 +170,7 @@ def _prepare_frag_download(self, ctx):
                 total_frags_str += ' (not including %d ad)' % ad_frags
         else:
             total_frags_str = 'unknown (live)'
-        self.to_screen(
+        self.to_screen(f'[{self.FD_NAME}] Total fragments: {total_frags_str}')
-            '[%s] Total fragments: %s' % (self.FD_NAME, total_frags_str))
         self.report_destination(ctx['filename'])
         dl = HttpQuietDownloader(
             self.ydl,
@@ -342,8 +339,7 @@ def _prepare_external_frag_download(self, ctx):
                 total_frags_str += ' (not including %d ad)' % ad_frags
         else:
             total_frags_str = 'unknown (live)'
-        self.to_screen(
+        self.to_screen(f'[{self.FD_NAME}] Total fragments: {total_frags_str}')
-            '[%s] Total fragments: %s' % (self.FD_NAME, total_frags_str))
 
         tmpfilename = self.temp_name(ctx['filename'])
 

yt_dlp/downloader/hls.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import re
 import io
 import binascii
@@ -102,8 +100,7 @@ def real_download(self, filename, info_dict):
         if real_downloader and not real_downloader.supports_manifest(s):
             real_downloader = None
         if real_downloader:
-            self.to_screen(
+            self.to_screen(f'[{self.FD_NAME}] Fragment downloads will be delegated to {real_downloader.get_basename()}')
-                '[%s] Fragment downloads will be delegated to %s' % (self.FD_NAME, real_downloader.get_basename()))
 
         def is_ad_fragment_start(s):
             return (s.startswith('#ANVATO-SEGMENT-INFO') and 'type=ad' in s

yt_dlp/downloader/http.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import os
 import ssl
 import time
@@ -221,10 +219,12 @@ def download():
                 min_data_len = self.params.get('min_filesize')
                 max_data_len = self.params.get('max_filesize')
                 if min_data_len is not None and data_len < min_data_len:
-                    self.to_screen('\r[download] File is smaller than min-filesize (%s bytes < %s bytes). Aborting.' % (data_len, min_data_len))
+                    self.to_screen(
+                        f'\r[download] File is smaller than min-filesize ({data_len} bytes < {min_data_len} bytes). Aborting.')
                     return False
                 if max_data_len is not None and data_len > max_data_len:
-                    self.to_screen('\r[download] File is larger than max-filesize (%s bytes > %s bytes). Aborting.' % (data_len, max_data_len))
+                    self.to_screen(
+                        f'\r[download] File is larger than max-filesize ({data_len} bytes > {max_data_len} bytes). Aborting.')
                     return False
 
             byte_counter = 0 + ctx.resume_len
@@ -265,7 +265,7 @@ def retry(e):
                         assert ctx.stream is not None
                         ctx.filename = self.undo_temp_name(ctx.tmpfilename)
                         self.report_destination(ctx.filename)
-                    except (OSError, IOError) as err:
+                    except OSError as err:
                         self.report_error('unable to open for writing: %s' % str(err))
                         return False
 
@@ -277,7 +277,7 @@ def retry(e):
 
                 try:
                     ctx.stream.write(data_block)
-                except (IOError, OSError) as err:
+                except OSError as err:
                     self.to_stderr('\n')
                     self.report_error('unable to write data: %s' % str(err))
                     return False

yt_dlp/downloader/ism.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import time
 import binascii
 import io

yt_dlp/downloader/mhtml.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import io
 import quopri
 import re

yt_dlp/downloader/niconico.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import threading
 
 from .common import FileDownloader

yt_dlp/downloader/rtmp.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import os
 import re
 import subprocess

yt_dlp/downloader/rtsp.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import os
 import subprocess
 
@@ -32,7 +30,7 @@ def real_download(self, filename, info_dict):
         retval = subprocess.call(args)
         if retval == 0:
             fsize = os.path.getsize(encodeFilename(tmpfilename))
-            self.to_screen('\r[%s] %s bytes' % (args[0], fsize))
+            self.to_screen(f'\r[{args[0]}] {fsize} bytes')
             self.try_rename(tmpfilename, filename)
             self._hook_progress({
                 'downloaded_bytes': fsize,

yt_dlp/downloader/youtube_live_chat.py

@@ -1,5 +1,3 @@
-from __future__ import division, unicode_literals
-
 import json
 import time
 

yt_dlp/extractor/abc.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import hashlib
 import hmac
 import re

yt_dlp/extractor/abcnews.py

@@ -1,7 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
-
 from .amp import AMPIE
 from .common import InfoExtractor
 from ..utils import (

yt_dlp/extractor/abcotvs.py

@@ -1,7 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
-
 from .common import InfoExtractor
 from ..compat import compat_str
 from ..utils import (

yt_dlp/extractor/academicearth.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import re
 
 from .common import InfoExtractor

yt_dlp/extractor/acast.py

@@ -1,7 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
-
 from .common import InfoExtractor
 from ..utils import (
     clean_html,

yt_dlp/extractor/adn.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import base64
 import binascii
 import json

yt_dlp/extractor/adobeconnect.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..compat import (
     compat_parse_qs,

yt_dlp/extractor/adobepass.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import json
 import re
 import time

yt_dlp/extractor/adobetv.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import functools
 import re
 

yt_dlp/extractor/adultswim.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import json
 
 from .turner import TurnerBaseIE

yt_dlp/extractor/aenetworks.py

@@ -1,7 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
-
 from .theplatform import ThePlatformIE
 from ..utils import (
     ExtractorError,

yt_dlp/extractor/afreecatv.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import functools
 import re
 

yt_dlp/extractor/airmozilla.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 
 from .common import InfoExtractor

yt_dlp/extractor/aliexpress.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..compat import compat_str
 from ..utils import (

yt_dlp/extractor/aljazeera.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import json
 
 from .common import InfoExtractor

yt_dlp/extractor/allocine.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..compat import compat_str
 from ..utils import (

yt_dlp/extractor/alphaporno.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..utils import (
     parse_iso8601,

yt_dlp/extractor/alsace20tv.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..utils import (
     clean_html,

yt_dlp/extractor/alura.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 
 from .common import InfoExtractor

yt_dlp/extractor/amara.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from .youtube import YoutubeIE
 from .vimeo import VimeoIE

yt_dlp/extractor/amazon.py

@@ -1,4 +1,3 @@
-# coding: utf-8
 from .common import InfoExtractor
 from ..utils import int_or_none
 

yt_dlp/extractor/amcnetworks.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 
 from .theplatform import ThePlatformIE

yt_dlp/extractor/americastestkitchen.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import json
 
 from .common import InfoExtractor

yt_dlp/extractor/amp.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 from ..utils import (
     determine_ext,

yt_dlp/extractor/animelab.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 
 from ..utils import (

yt_dlp/extractor/animeondemand.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import re
 
 from .common import InfoExtractor

yt_dlp/extractor/ant1newsgr.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 import urllib.parse
 

yt_dlp/extractor/anvato.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import base64
 import hashlib
 import json

yt_dlp/extractor/anvato_token_generator/__init__.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from .nfl import NFLTokenGenerator
 
 __all__ = [

yt_dlp/extractor/anvato_token_generator/common.py

@@ -1,6 +1,3 @@
-from __future__ import unicode_literals
-
-
 class TokenGenerator:
     def generate(self, anvack, mcp_id):
         raise NotImplementedError('This method must be implemented by subclasses')

yt_dlp/extractor/anvato_token_generator/nfl.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 import json
 
 from .common import TokenGenerator

yt_dlp/extractor/aol.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 
 from .yahoo import YahooIE

yt_dlp/extractor/apa.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 
 from .common import InfoExtractor