diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index d8d8c1435..4c1004973 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -89,7 +89,6 @@ from .utils import (
     version_tuple,
     write_json_file,
     write_string,
-    YoutubeDLCookieJar,
     YoutubeDLCookieProcessor,
     YoutubeDLHandler,
     YoutubeDLRedirectHandler,
diff --git a/youtube_dl/compat.py b/youtube_dl/compat.py
index 27b0ead30..7a4f832f3 100644
--- a/youtube_dl/compat.py
+++ b/youtube_dl/compat.py
@@ -2926,9 +2926,9 @@ except TypeError:  # Python 2.6
 
 
 try:
-    from tempfile import TemporaryDirectory as Compat_TemporaryDirectory
+    from tempfile import TemporaryDirectory as compat_TemporaryDirectory
 except ImportError:
-    class Compat_TemporaryDirectory:
+    class compat_TemporaryDirectory:
         def __init__(self, prefix=None):
             self._prefix = prefix
             self._path = None
diff --git a/youtube_dl/cookies.py b/youtube_dl/cookies.py
index 5e9ca0563..362b12233 100644
--- a/youtube_dl/cookies.py
+++ b/youtube_dl/cookies.py
@@ -11,7 +11,7 @@ import warnings
 from datetime import datetime, timedelta
 
 from youtube_dl.aes import aes_cbc_decrypt
-from youtube_dl.compat import compat_cookiejar_Cookie, compat_b64decode, Compat_TemporaryDirectory
+from youtube_dl.compat import compat_cookiejar_Cookie, compat_b64decode, compat_TemporaryDirectory
 from youtube_dl.utils import YoutubeDLCookieJar, expand_path, bytes_to_intlist, intlist_to_bytes
 
 try:
@@ -87,7 +87,7 @@ def _extract_firefox_cookies(profile, logger):
         raise FileNotFoundError('could not find firefox cookies database in {}'.format(search_root))
     logger.debug('extracting from: "{}"'.format(cookie_database_path))
 
-    with Compat_TemporaryDirectory(prefix='youtube_dl') as tmpdir:
+    with compat_TemporaryDirectory(prefix='youtube_dl') as tmpdir:
         cursor = None
         try:
             cursor = _open_database_copy(cookie_database_path, tmpdir)
@@ -200,7 +200,7 @@ def _extract_chrome_cookies(browser_name, profile, logger):
 
     decryptor = get_cookie_decryptor(config['browser_dir'], config['keyring_name'], logger)
 
-    with Compat_TemporaryDirectory(prefix='youtube_dl') as tmpdir:
+    with compat_TemporaryDirectory(prefix='youtube_dl') as tmpdir:
         cursor = None
         try:
             cursor = _open_database_copy(cookie_database_path, tmpdir)
@@ -491,7 +491,7 @@ def _parse_safari_cookies_record(data, jar, logger):
     value_offset = p.read_uint()
     p.skip(8, 'unknown record field 3')
     expiration_date = _mac_absolute_time_to_posix(p.read_double())
-    _creation_date = _mac_absolute_time_to_posix(p.read_double())
+    _creation_date = _mac_absolute_time_to_posix(p.read_double())  # noqa: F841
 
     try:
         p.skip_to(domain_offset)