[youtube] Fix uploader for collaborative playlists (#3332)

Authored by: coletdjnz

yt_dlp/extractor/common.py

@@ -23,6 +23,7 @@ from ..compat import (
     compat_getpass,
     compat_http_client,
     compat_os_name,
+    compat_Pattern,
     compat_str,
     compat_urllib_error,
     compat_urllib_parse_unquote,
@@ -41,7 +42,6 @@ from ..utils import (
     base_url,
     bug_reports_message,
     clean_html,
-    compiled_regex_type,
     determine_ext,
     determine_protocol,
     dict_get,
@@ -1203,7 +1203,9 @@ class InfoExtractor(object):
         In case of failure return a default value or raise a WARNING or a
         RegexNotFoundError, depending on fatal, specifying the field name.
         """
-        if isinstance(pattern, (str, compat_str, compiled_regex_type)):
+        if string is None:
+            mobj = None
+        elif isinstance(pattern, (str, compat_Pattern)):
             mobj = re.search(pattern, string, flags)
         else:
             for p in pattern: