diff --git a/gallery_dl/extractor/2ch.py b/gallery_dl/extractor/2ch.py
index 1f17c993..ab55e2cf 100644
--- a/gallery_dl/extractor/2ch.py
+++ b/gallery_dl/extractor/2ch.py
@@ -20,7 +20,7 @@ class _2chThreadExtractor(Extractor):
     directory_fmt = ("{category}", "{board}", "{thread} {title}")
     filename_fmt = "{tim}{filename:? //}.{extension}"
     archive_fmt = "{board}_{thread}_{tim}"
-    pattern = rf"{BASE_PATTERN}/([^/?#]+)/res/(\d+)"
+    pattern = BASE_PATTERN + r"/([^/?#]+)/res/(\d+)"
     example = "https://2ch.org/a/res/12345.html"
 
     def __init__(self, match):
@@ -66,7 +66,7 @@ class _2chBoardExtractor(Extractor):
     category = "2ch"
     subcategory = "board"
     root = "https://2ch.org"
-    pattern = rf"{BASE_PATTERN}/([^/?#]+)/?$"
+    pattern = BASE_PATTERN + r"/([^/?#]+)/?$"
     example = "https://2ch.org/a/"
 
     def __init__(self, match):
diff --git a/gallery_dl/extractor/audiochan.py b/gallery_dl/extractor/audiochan.py
index b708ce76..ccd05f35 100644
--- a/gallery_dl/extractor/audiochan.py
+++ b/gallery_dl/extractor/audiochan.py
@@ -103,7 +103,7 @@ class AudiochanExtractor(Extractor):
 
 class AudiochanAudioExtractor(AudiochanExtractor):
     subcategory = "audio"
-    pattern = rf"{BASE_PATTERN}/a/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/a/([^/?#]+)"
     example = "https://audiochan.com/a/SLUG"
 
     def posts(self):
@@ -114,7 +114,7 @@ class AudiochanAudioExtractor(AudiochanExtractor):
 
 class AudiochanUserExtractor(AudiochanExtractor):
     subcategory = "user"
-    pattern = rf"{BASE_PATTERN}/u/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/u/([^/?#]+)"
     example = "https://audiochan.com/u/USER"
 
     def posts(self):
@@ -130,7 +130,7 @@ class AudiochanUserExtractor(AudiochanExtractor):
 
 class AudiochanCollectionExtractor(AudiochanExtractor):
     subcategory = "collection"
-    pattern = rf"{BASE_PATTERN}/c/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/c/([^/?#]+)"
     example = "https://audiochan.com/c/SLUG"
 
     def posts(self):
@@ -146,7 +146,7 @@ class AudiochanCollectionExtractor(AudiochanExtractor):
 
 class AudiochanSearchExtractor(AudiochanExtractor):
     subcategory = "search"
-    pattern = rf"{BASE_PATTERN}/search/?\?([^#]+)"
+    pattern = BASE_PATTERN + r"/search/?\?([^#]+)"
     example = "https://audiochan.com/search?q=QUERY"
 
     def posts(self):
diff --git a/gallery_dl/extractor/bellazon.py b/gallery_dl/extractor/bellazon.py
index 33f4ad31..9757f487 100644
--- a/gallery_dl/extractor/bellazon.py
+++ b/gallery_dl/extractor/bellazon.py
@@ -192,8 +192,8 @@ class BellazonExtractor(Extractor):
 
 class BellazonPostExtractor(BellazonExtractor):
     subcategory = "post"
-    pattern = (rf"{BASE_PATTERN}(/topic/\d+-[\w-]+(?:/page/\d+)?)"
-               rf"/?#(?:findC|c)omment-(\d+)")
+    pattern = (BASE_PATTERN + r"(/topic/\d+-[\w-]+(?:/page/\d+)?)"
+               r"/?#(?:findC|c)omment-(\d+)")
     example = "https://www.bellazon.com/main/topic/123-SLUG/#findComment-12345"
 
     def posts(self):
@@ -211,7 +211,7 @@ class BellazonPostExtractor(BellazonExtractor):
 
 class BellazonThreadExtractor(BellazonExtractor):
     subcategory = "thread"
-    pattern = rf"{BASE_PATTERN}(/topic/\d+-[\w-]+)(?:/page/(\d+))?"
+    pattern = BASE_PATTERN + r"(/topic/\d+-[\w-]+)(?:/page/(\d+))?"
     example = "https://www.bellazon.com/main/topic/123-SLUG/"
 
     def posts(self):
@@ -236,7 +236,7 @@ class BellazonThreadExtractor(BellazonExtractor):
 
 class BellazonForumExtractor(BellazonExtractor):
     subcategory = "forum"
-    pattern = rf"{BASE_PATTERN}(/forum/\d+-[\w-]+)(?:/page/(\d+))?"
+    pattern = BASE_PATTERN + r"(/forum/\d+-[\w-]+)(?:/page/(\d+))?"
     example = "https://www.bellazon.com/main/forum/123-SLUG/"
 
     def items(self):
diff --git a/gallery_dl/extractor/cyberfile.py b/gallery_dl/extractor/cyberfile.py
index e8c0061f..6af3fd23 100644
--- a/gallery_dl/extractor/cyberfile.py
+++ b/gallery_dl/extractor/cyberfile.py
@@ -48,7 +48,7 @@ class CyberfileExtractor(Extractor):
 
 class CyberfileFolderExtractor(CyberfileExtractor):
     subcategory = "folder"
-    pattern = rf"{BASE_PATTERN}/folder/([0-9a-f]+)"
+    pattern = BASE_PATTERN + r"/folder/([0-9a-f]+)"
     example = "https://cyberfile.me/folder/0123456789abcdef/NAME"
 
     def items(self):
@@ -97,7 +97,7 @@ class CyberfileFolderExtractor(CyberfileExtractor):
 
 class CyberfileSharedExtractor(CyberfileExtractor):
     subcategory = "shared"
-    pattern = rf"{BASE_PATTERN}/shared/([a-zA-Z0-9]+)"
+    pattern = BASE_PATTERN + r"/shared/([a-zA-Z0-9]+)"
     example = "https://cyberfile.me/shared/AbCdEfGhIjK"
 
     def items(self):
@@ -129,7 +129,7 @@ class CyberfileSharedExtractor(CyberfileExtractor):
 class CyberfileFileExtractor(CyberfileExtractor):
     subcategory = "file"
     directory_fmt = ("{category}", "{uploader}", "{folder}")
-    pattern = rf"{BASE_PATTERN}/([a-zA-Z0-9]+)"
+    pattern = BASE_PATTERN + r"/([a-zA-Z0-9]+)"
     example = "https://cyberfile.me/AbCdE"
 
     def items(self):
diff --git a/gallery_dl/extractor/danbooru.py b/gallery_dl/extractor/danbooru.py
index 06ea6e81..c036226e 100644
--- a/gallery_dl/extractor/danbooru.py
+++ b/gallery_dl/extractor/danbooru.py
@@ -349,7 +349,7 @@ class DanbooruMediaassetExtractor(DanbooruExtractor):
     subcategory = "media-asset"
     filename_fmt = "{category}_ma{id}_{filename}.{extension}"
     archive_fmt = "m{id}"
-    pattern = rf"{BASE_PATTERN}/media_assets/(\d+)"
+    pattern = BASE_PATTERN + r"/media_assets/(\d+)"
     example = "https://danbooru.donmai.us/media_assets/12345"
 
     def posts(self):
diff --git a/gallery_dl/extractor/dandadan.py b/gallery_dl/extractor/dandadan.py
index 48dc0b7c..44db1606 100644
--- a/gallery_dl/extractor/dandadan.py
+++ b/gallery_dl/extractor/dandadan.py
@@ -22,7 +22,7 @@ class DandadanBase():
 
 class DandadanChapterExtractor(DandadanBase, ChapterExtractor):
     """Extractor for dandadan manga chapters"""
-    pattern = rf"{BASE_PATTERN}(/manga/dandadan-chapter-([^/?#]+)/?)"
+    pattern = BASE_PATTERN + r"(/manga/dandadan-chapter-([^/?#]+)/?)"
     example = "https://dandadan.net/manga/dandadan-chapter-123/"
 
     def metadata(self, page):
@@ -54,7 +54,7 @@ class DandadanChapterExtractor(DandadanBase, ChapterExtractor):
 class DandadanMangaExtractor(DandadanBase, MangaExtractor):
     """Extractor for dandadan manga"""
     chapterclass = DandadanChapterExtractor
-    pattern = rf"{BASE_PATTERN}(/)"
+    pattern = BASE_PATTERN + r"(/)"
     example = "https://dandadan.net/"
 
     def chapters(self, page):
diff --git a/gallery_dl/extractor/e621.py b/gallery_dl/extractor/e621.py
index fa318899..08cab001 100644
--- a/gallery_dl/extractor/e621.py
+++ b/gallery_dl/extractor/e621.py
@@ -145,7 +145,7 @@ class E621PopularExtractor(E621Extractor, danbooru.DanbooruPopularExtractor):
 class E621ArtistExtractor(E621Extractor, danbooru.DanbooruArtistExtractor):
     """Extractor for e621 artists"""
     subcategory = "artist"
-    pattern = rf"{BASE_PATTERN}/artists/(\d+)"
+    pattern = BASE_PATTERN + r"/artists/(\d+)"
     example = "https://e621.net/artists/12345"
 
     items = E621Extractor.items_artists
@@ -155,7 +155,7 @@ class E621ArtistSearchExtractor(E621Extractor,
                                 danbooru.DanbooruArtistSearchExtractor):
     """Extractor for e621 artist searches"""
     subcategory = "artist-search"
-    pattern = rf"{BASE_PATTERN}/artists/?\?([^#]+)"
+    pattern = BASE_PATTERN + r"/artists/?\?([^#]+)"
     example = "https://e621.net/artists?QUERY"
 
     items = E621Extractor.items_artists
diff --git a/gallery_dl/extractor/fansly.py b/gallery_dl/extractor/fansly.py
index ba60b158..6a88328b 100644
--- a/gallery_dl/extractor/fansly.py
+++ b/gallery_dl/extractor/fansly.py
@@ -155,7 +155,7 @@ class FanslyExtractor(Extractor):
 
 class FanslyPostExtractor(FanslyExtractor):
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/post/(\d+)"
+    pattern = BASE_PATTERN + r"/post/(\d+)"
     example = "https://fansly.com/post/1234567890"
 
     def posts(self):
@@ -164,7 +164,7 @@ class FanslyPostExtractor(FanslyExtractor):
 
 class FanslyHomeExtractor(FanslyExtractor):
     subcategory = "home"
-    pattern = rf"{BASE_PATTERN}/home(?:/(?:subscribed()|list/(\d+)))?"
+    pattern = BASE_PATTERN + r"/home(?:/(?:subscribed()|list/(\d+)))?"
     example = "https://fansly.com/home"
 
     def posts(self):
@@ -180,7 +180,7 @@ class FanslyHomeExtractor(FanslyExtractor):
 
 class FanslyListExtractor(FanslyExtractor):
     subcategory = "list"
-    pattern = rf"{BASE_PATTERN}/lists/(\d+)"
+    pattern = BASE_PATTERN + r"/lists/(\d+)"
     example = "https://fansly.com/lists/1234567890"
 
     def items(self):
@@ -193,7 +193,7 @@ class FanslyListExtractor(FanslyExtractor):
 
 class FanslyListsExtractor(FanslyExtractor):
     subcategory = "lists"
-    pattern = rf"{BASE_PATTERN}/lists"
+    pattern = BASE_PATTERN + r"/lists"
     example = "https://fansly.com/lists"
 
     def items(self):
@@ -206,7 +206,7 @@ class FanslyListsExtractor(FanslyExtractor):
 
 class FanslyCreatorPostsExtractor(FanslyExtractor):
     subcategory = "creator-posts"
-    pattern = rf"{BASE_PATTERN}/([^/?#]+)/posts(?:/wall/(\d+))?"
+    pattern = BASE_PATTERN + r"/([^/?#]+)/posts(?:/wall/(\d+))?"
     example = "https://fansly.com/CREATOR/posts"
 
     def posts_wall(self, account, wall):
@@ -215,7 +215,7 @@ class FanslyCreatorPostsExtractor(FanslyExtractor):
 
 class FanslyCreatorMediaExtractor(FanslyExtractor):
     subcategory = "creator-media"
-    pattern = rf"{BASE_PATTERN}/([^/?#]+)/media(?:/wall/(\d+))?"
+    pattern = BASE_PATTERN + r"/([^/?#]+)/media(?:/wall/(\d+))?"
     example = "https://fansly.com/CREATOR/media"
 
     def posts_wall(self, account, wall):
diff --git a/gallery_dl/extractor/fikfap.py b/gallery_dl/extractor/fikfap.py
index 75071c56..5a0f4347 100644
--- a/gallery_dl/extractor/fikfap.py
+++ b/gallery_dl/extractor/fikfap.py
@@ -67,7 +67,7 @@ class FikfapExtractor(Extractor):
 
 class FikfapPostExtractor(FikfapExtractor):
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/user/(\w+)/post/(\d+)"
+    pattern = BASE_PATTERN + r"/user/(\w+)/post/(\d+)"
     example = "https://fikfap.com/user/USER/post/12345"
 
     def posts(self):
@@ -86,7 +86,7 @@ class FikfapPostExtractor(FikfapExtractor):
 
 class FikfapUserExtractor(FikfapExtractor):
     subcategory = "user"
-    pattern = rf"{BASE_PATTERN}/user/(\w+)"
+    pattern = BASE_PATTERN + r"/user/(\w+)"
     example = "https://fikfap.com/user/USER"
 
     def posts(self):
diff --git a/gallery_dl/extractor/fitnakedgirls.py b/gallery_dl/extractor/fitnakedgirls.py
index d252ec4f..a1ebf48a 100644
--- a/gallery_dl/extractor/fitnakedgirls.py
+++ b/gallery_dl/extractor/fitnakedgirls.py
@@ -50,7 +50,7 @@ class FitnakedgirlsGalleryExtractor(GalleryExtractor, FitnakedgirlsExtractor):
     directory_fmt = ("{category}", "{title}")
     filename_fmt = "{filename}.{extension}"
     archive_fmt = "{gallery_id}_{filename}"
-    pattern = rf"{BASE_PATTERN}/photos/gallery/([\w-]+)/?$"
+    pattern = BASE_PATTERN + r"/photos/gallery/([\w-]+)/?$"
     example = "https://fitnakedgirls.com/photos/gallery/MODEL-nude/"
 
     def __init__(self, match):
@@ -110,7 +110,7 @@ class FitnakedgirlsGalleryExtractor(GalleryExtractor, FitnakedgirlsExtractor):
 class FitnakedgirlsCategoryExtractor(FitnakedgirlsExtractor):
     """Extractor for fitnakedgirls category pages"""
     subcategory = "category"
-    pattern = rf"{BASE_PATTERN}/photos/gallery/category/([\w-]+)"
+    pattern = BASE_PATTERN + r"/photos/gallery/category/([\w-]+)"
     example = "https://fitnakedgirls.com/photos/gallery/category/CATEGORY/"
 
     def galleries(self):
@@ -121,7 +121,7 @@ class FitnakedgirlsCategoryExtractor(FitnakedgirlsExtractor):
 class FitnakedgirlsTagExtractor(FitnakedgirlsExtractor):
     """Extractor for fitnakedgirls tag pages"""
     subcategory = "tag"
-    pattern = rf"{BASE_PATTERN}/photos/gallery/tag/([\w-]+)"
+    pattern = BASE_PATTERN + r"/photos/gallery/tag/([\w-]+)"
     example = "https://fitnakedgirls.com/photos/gallery/tag/TAG/"
 
     def galleries(self):
@@ -135,7 +135,7 @@ class FitnakedgirlsVideoExtractor(FitnakedgirlsExtractor):
     directory_fmt = ("{category}", "{title}")
     filename_fmt = "{filename}.{extension}"
     archive_fmt = "{video_id}_{filename}"
-    pattern = rf"{BASE_PATTERN}/videos/(\d+)/(\d+)/([\w-]+)"
+    pattern = BASE_PATTERN + r"/videos/(\d+)/(\d+)/([\w-]+)"
     example = "https://fitnakedgirls.com/videos/2025/08/VIDEO-TITLE/"
 
     def items(self):
@@ -168,7 +168,7 @@ class FitnakedgirlsBlogExtractor(FitnakedgirlsExtractor):
     directory_fmt = ("{category}", "{title}")
     filename_fmt = "{filename}.{extension}"
     archive_fmt = "{post_id}_{filename}"
-    pattern = rf"{BASE_PATTERN}/fitblog/([\w-]+)"
+    pattern = BASE_PATTERN + r"/fitblog/([\w-]+)"
     example = "https://fitnakedgirls.com/fitblog/MODEL-NAME/"
 
     def items(self):
diff --git a/gallery_dl/extractor/hdoujin.py b/gallery_dl/extractor/hdoujin.py
index 080b8997..927aea2b 100644
--- a/gallery_dl/extractor/hdoujin.py
+++ b/gallery_dl/extractor/hdoujin.py
@@ -23,19 +23,19 @@ class HdoujinBase():
 
 class HdoujinGalleryExtractor(
         HdoujinBase, schalenetwork.SchalenetworkGalleryExtractor):
-    pattern = rf"{BASE_PATTERN}/(?:g|reader)/(\d+)/(\w+)"
+    pattern = BASE_PATTERN + r"/(?:g|reader)/(\d+)/(\w+)"
     example = "https://hdoujin.org/g/12345/67890abcdef/"
 
 
 class HdoujinSearchExtractor(
         HdoujinBase, schalenetwork.SchalenetworkSearchExtractor):
-    pattern = rf"{BASE_PATTERN}/(?:tag/([^/?#]+)|browse)?(?:/?\?([^#]*))?$"
+    pattern = BASE_PATTERN + r"/(?:tag/([^/?#]+)|browse)?(?:/?\?([^#]*))?$"
     example = "https://hdoujin.org/browse?s=QUERY"
 
 
 class HdoujinFavoriteExtractor(
         HdoujinBase, schalenetwork.SchalenetworkFavoriteExtractor):
-    pattern = rf"{BASE_PATTERN}/favorites(?:\?([^#]*))?"
+    pattern = BASE_PATTERN + r"/favorites(?:\?([^#]*))?"
     example = "https://hdoujin.org/favorites"
 
 
diff --git a/gallery_dl/extractor/imgpile.py b/gallery_dl/extractor/imgpile.py
index f6342038..c991abed 100644
--- a/gallery_dl/extractor/imgpile.py
+++ b/gallery_dl/extractor/imgpile.py
@@ -28,7 +28,7 @@ class ImgpileExtractor(Extractor):
 
 class ImgpilePostExtractor(ImgpileExtractor):
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/p/(\w+)"
+    pattern = BASE_PATTERN + r"/p/(\w+)"
     example = "https://imgpile.com/p/AbCdEfG"
 
     def items(self):
@@ -78,7 +78,7 @@ class ImgpilePostExtractor(ImgpileExtractor):
 
 class ImgpileUserExtractor(ImgpileExtractor):
     subcategory = "user"
-    pattern = rf"{BASE_PATTERN}/u/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/u/([^/?#]+)"
     example = "https://imgpile.com/u/USER"
 
     def items(self):
diff --git a/gallery_dl/extractor/instagram.py b/gallery_dl/extractor/instagram.py
index 9f0ad790..d087b3d6 100644
--- a/gallery_dl/extractor/instagram.py
+++ b/gallery_dl/extractor/instagram.py
@@ -632,7 +632,7 @@ class InstagramCollectionExtractor(InstagramExtractor):
 class InstagramStoriesTrayExtractor(InstagramExtractor):
     """Extractor for your Instagram account's stories tray"""
     subcategory = "stories-tray"
-    pattern = rf"{BASE_PATTERN}/stories/me/?$()"
+    pattern = BASE_PATTERN + r"/stories/me/?$()"
     example = "https://www.instagram.com/stories/me/"
 
     def items(self):
diff --git a/gallery_dl/extractor/iwara.py b/gallery_dl/extractor/iwara.py
index d9d1cf0a..595c55fe 100644
--- a/gallery_dl/extractor/iwara.py
+++ b/gallery_dl/extractor/iwara.py
@@ -12,7 +12,7 @@ from ..cache import cache, memcache
 import hashlib
 
 BASE_PATTERN = r"(?:https?://)?(?:www\.)?iwara\.tv"
-USER_PATTERN = rf"{BASE_PATTERN}/profile/([^/?#]+)"
+USER_PATTERN = BASE_PATTERN + r"/profile/([^/?#]+)"
 
 
 class IwaraExtractor(Extractor):
@@ -158,7 +158,7 @@ class IwaraExtractor(Extractor):
 
 class IwaraUserExtractor(Dispatch, IwaraExtractor):
     """Extractor for iwara.tv profile pages"""
-    pattern = rf"{USER_PATTERN}/?$"
+    pattern = USER_PATTERN + r"/?$"
     example = "https://www.iwara.tv/profile/USERNAME"
 
     def items(self):
@@ -172,7 +172,7 @@ class IwaraUserExtractor(Dispatch, IwaraExtractor):
 
 class IwaraUserImagesExtractor(IwaraExtractor):
     subcategory = "user-images"
-    pattern = rf"{USER_PATTERN}/images(?:\?([^#]+))?"
+    pattern = USER_PATTERN + r"/images(?:\?([^#]+))?"
     example = "https://www.iwara.tv/profile/USERNAME/images"
 
     def items(self):
@@ -182,7 +182,7 @@ class IwaraUserImagesExtractor(IwaraExtractor):
 
 class IwaraUserVideosExtractor(IwaraExtractor):
     subcategory = "user-videos"
-    pattern = rf"{USER_PATTERN}/videos(?:\?([^#]+))?"
+    pattern = USER_PATTERN + r"/videos(?:\?([^#]+))?"
     example = "https://www.iwara.tv/profile/USERNAME/videos"
 
     def items(self):
@@ -192,7 +192,7 @@ class IwaraUserVideosExtractor(IwaraExtractor):
 
 class IwaraUserPlaylistsExtractor(IwaraExtractor):
     subcategory = "user-playlists"
-    pattern = rf"{USER_PATTERN}/playlists(?:\?([^#]+))?"
+    pattern = USER_PATTERN + r"/playlists(?:\?([^#]+))?"
     example = "https://www.iwara.tv/profile/USERNAME/playlists"
 
     def items(self):
@@ -207,7 +207,7 @@ class IwaraUserPlaylistsExtractor(IwaraExtractor):
 
 class IwaraFollowingExtractor(IwaraExtractor):
     subcategory = "following"
-    pattern = rf"{USER_PATTERN}/following"
+    pattern = USER_PATTERN + r"/following"
     example = "https://www.iwara.tv/profile/USERNAME/following"
 
     def items(self):
@@ -217,7 +217,7 @@ class IwaraFollowingExtractor(IwaraExtractor):
 
 class IwaraFollowersExtractor(IwaraExtractor):
     subcategory = "followers"
-    pattern = rf"{USER_PATTERN}/followers"
+    pattern = USER_PATTERN + r"/followers"
     example = "https://www.iwara.tv/profile/USERNAME/followers"
 
     def items(self):
@@ -228,7 +228,7 @@ class IwaraFollowersExtractor(IwaraExtractor):
 class IwaraImageExtractor(IwaraExtractor):
     """Extractor for individual iwara.tv image pages"""
     subcategory = "image"
-    pattern = rf"{BASE_PATTERN}/image/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/image/([^/?#]+)"
     example = "https://www.iwara.tv/image/ID"
 
     def items(self):
@@ -238,7 +238,7 @@ class IwaraImageExtractor(IwaraExtractor):
 class IwaraVideoExtractor(IwaraExtractor):
     """Extractor for individual iwara.tv videos"""
     subcategory = "video"
-    pattern = rf"{BASE_PATTERN}/video/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/video/([^/?#]+)"
     example = "https://www.iwara.tv/video/ID"
 
     def items(self):
@@ -248,7 +248,7 @@ class IwaraVideoExtractor(IwaraExtractor):
 class IwaraPlaylistExtractor(IwaraExtractor):
     """Extractor for individual iwara.tv playlist pages"""
     subcategory = "playlist"
-    pattern = rf"{BASE_PATTERN}/playlist/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/playlist/([^/?#]+)"
     example = "https://www.iwara.tv/playlist/ID"
 
     def items(self):
@@ -257,7 +257,7 @@ class IwaraPlaylistExtractor(IwaraExtractor):
 
 class IwaraFavoriteExtractor(IwaraExtractor):
     subcategory = "favorite"
-    pattern = rf"{BASE_PATTERN}/favorites(?:/(image|video)s)?"
+    pattern = BASE_PATTERN + r"/favorites(?:/(image|video)s)?"
     example = "https://www.iwara.tv/favorites/videos"
 
     def items(self):
@@ -268,7 +268,7 @@ class IwaraFavoriteExtractor(IwaraExtractor):
 class IwaraSearchExtractor(IwaraExtractor):
     """Extractor for iwara.tv search pages"""
     subcategory = "search"
-    pattern = rf"{BASE_PATTERN}/search\?([^#]+)"
+    pattern = BASE_PATTERN + r"/search\?([^#]+)"
     example = "https://www.iwara.tv/search?query=QUERY&type=TYPE"
 
     def items(self):
@@ -281,7 +281,7 @@ class IwaraSearchExtractor(IwaraExtractor):
 class IwaraTagExtractor(IwaraExtractor):
     """Extractor for iwara.tv tag search"""
     subcategory = "tag"
-    pattern = rf"{BASE_PATTERN}/(image|video)s(?:\?([^#]+))?"
+    pattern = BASE_PATTERN + r"/(image|video)s(?:\?([^#]+))?"
     example = "https://www.iwara.tv/videos?tags=TAGS"
 
     def items(self):
diff --git a/gallery_dl/extractor/kemono.py b/gallery_dl/extractor/kemono.py
index bf35670e..d58ef757 100644
--- a/gallery_dl/extractor/kemono.py
+++ b/gallery_dl/extractor/kemono.py
@@ -16,7 +16,7 @@ import json
 
 BASE_PATTERN = (r"(?:https?://)?(?:www\.|beta\.)?"
                 r"(kemono|coomer)\.(cr|s[tu]|party)")
-USER_PATTERN = rf"{BASE_PATTERN}/([^/?#]+)/user/([^/?#]+)"
+USER_PATTERN = BASE_PATTERN + r"/([^/?#]+)/user/([^/?#]+)"
 HASH_PATTERN = r"/[0-9a-f]{2}/[0-9a-f]{2}/([0-9a-f]{64})"
 
 
@@ -322,7 +322,7 @@ def _validate(response):
 class KemonoUserExtractor(KemonoExtractor):
     """Extractor for all posts from a kemono.cr user listing"""
     subcategory = "user"
-    pattern = rf"{USER_PATTERN}/?(?:\?([^#]+))?(?:$|\?|#)"
+    pattern = USER_PATTERN + r"/?(?:\?([^#]+))?(?:$|\?|#)"
     example = "https://kemono.cr/SERVICE/user/12345"
 
     def __init__(self, match):
@@ -345,7 +345,7 @@ class KemonoUserExtractor(KemonoExtractor):
 class KemonoPostsExtractor(KemonoExtractor):
     """Extractor for kemono.cr post listings"""
     subcategory = "posts"
-    pattern = rf"{BASE_PATTERN}/posts()()(?:/?\?([^#]+))?"
+    pattern = BASE_PATTERN + r"/posts()()(?:/?\?([^#]+))?"
     example = "https://kemono.cr/posts"
 
     def posts(self):
@@ -357,7 +357,7 @@ class KemonoPostsExtractor(KemonoExtractor):
 class KemonoPostExtractor(KemonoExtractor):
     """Extractor for a single kemono.cr post"""
     subcategory = "post"
-    pattern = rf"{USER_PATTERN}/post/([^/?#]+)(/revisions?(?:/(\d*))?)?"
+    pattern = USER_PATTERN + r"/post/([^/?#]+)(/revisions?(?:/(\d*))?)?"
     example = "https://kemono.cr/SERVICE/user/12345/post/12345"
 
     def __init__(self, match):
@@ -390,7 +390,7 @@ class KemonoDiscordExtractor(KemonoExtractor):
                      "{server_id} {server}", "{channel_id} {channel}")
     filename_fmt = "{id}_{num:>02}_{filename}.{extension}"
     archive_fmt = "discord_{server_id}_{id}_{num}"
-    pattern = rf"{BASE_PATTERN}/discord/server/(\d+)[/#](?:channel/)?(\d+)"
+    pattern = BASE_PATTERN + r"/discord/server/(\d+)[/#](?:channel/)?(\d+)"
     example = "https://kemono.cr/discord/server/12345/12345"
 
     def items(self):
@@ -460,7 +460,7 @@ class KemonoDiscordExtractor(KemonoExtractor):
 
 class KemonoDiscordServerExtractor(KemonoExtractor):
     subcategory = "discord-server"
-    pattern = rf"{BASE_PATTERN}/discord/server/(\d+)$"
+    pattern = BASE_PATTERN + r"/discord/server/(\d+)$"
     example = "https://kemono.cr/discord/server/12345"
 
     def items(self):
@@ -488,7 +488,7 @@ def discord_server_info(extr, server_id):
 class KemonoFavoriteExtractor(KemonoExtractor):
     """Extractor for kemono.cr favorites"""
     subcategory = "favorite"
-    pattern = rf"{BASE_PATTERN}/(?:account/)?favorites()()(?:/?\?([^#]+))?"
+    pattern = BASE_PATTERN + r"/(?:account/)?favorites()()(?:/?\?([^#]+))?"
     example = "https://kemono.cr/account/favorites/artists"
 
     def items(self):
@@ -536,7 +536,7 @@ class KemonoFavoriteExtractor(KemonoExtractor):
 class KemonoArtistsExtractor(KemonoExtractor):
     """Extractor for kemono artists"""
     subcategory = "artists"
-    pattern = rf"{BASE_PATTERN}/artists(?:\?([^#]+))?"
+    pattern = BASE_PATTERN + r"/artists(?:\?([^#]+))?"
     example = "https://kemono.cr/artists"
 
     def items(self):
diff --git a/gallery_dl/extractor/madokami.py b/gallery_dl/extractor/madokami.py
index e15b90d7..b429b40e 100644
--- a/gallery_dl/extractor/madokami.py
+++ b/gallery_dl/extractor/madokami.py
@@ -25,7 +25,7 @@ class MadokamiMangaExtractor(MadokamiExtractor):
     subcategory = "manga"
     directory_fmt = ("{category}", "{manga}")
     archive_fmt = "{chapter_id}"
-    pattern = rf"{BASE_PATTERN}/Manga/(\w/\w{{2}}/\w{{4}}/.+)"
+    pattern = BASE_PATTERN + r"/Manga/(\w/\w{2}/\w{4}/.+)"
     example = "https://manga.madokami.al/Manga/A/AB/ABCD/ABCDE_TITLE"
 
     def items(self):
diff --git a/gallery_dl/extractor/mangadex.py b/gallery_dl/extractor/mangadex.py
index 0a1709d7..98e8317f 100644
--- a/gallery_dl/extractor/mangadex.py
+++ b/gallery_dl/extractor/mangadex.py
@@ -83,8 +83,8 @@ class MangadexCoversExtractor(MangadexExtractor):
     directory_fmt = ("{category}", "{manga}", "Covers")
     filename_fmt = "{volume:>02}_{lang}.{extension}"
     archive_fmt = "c_{cover_id}"
-    pattern = (rf"{BASE_PATTERN}/(?:title|manga)/(?!follows|feed$)([0-9a-f-]+)"
-               rf"(?:/[^/?#]+)?\?tab=art")
+    pattern = (BASE_PATTERN + r"/(?:title|manga)/(?!follows|feed$)([0-9a-f-]+)"
+               r"(?:/[^/?#]+)?\?tab=art")
     example = ("https://mangadex.org/title"
                "/01234567-89ab-cdef-0123-456789abcdef?tab=art")
 
@@ -117,7 +117,7 @@ class MangadexCoversExtractor(MangadexExtractor):
 class MangadexChapterExtractor(MangadexExtractor):
     """Extractor for manga-chapters from mangadex.org"""
     subcategory = "chapter"
-    pattern = rf"{BASE_PATTERN}/chapter/([0-9a-f-]+)"
+    pattern = BASE_PATTERN + r"/chapter/([0-9a-f-]+)"
     example = ("https://mangadex.org/chapter"
                "/01234567-89ab-cdef-0123-456789abcdef")
 
@@ -156,7 +156,7 @@ class MangadexChapterExtractor(MangadexExtractor):
 class MangadexMangaExtractor(MangadexExtractor):
     """Extractor for manga from mangadex.org"""
     subcategory = "manga"
-    pattern = rf"{BASE_PATTERN}/(?:title|manga)/(?!follows|feed$)([0-9a-f-]+)"
+    pattern = BASE_PATTERN + r"/(?:title|manga)/(?!follows|feed$)([0-9a-f-]+)"
     example = ("https://mangadex.org/title"
                "/01234567-89ab-cdef-0123-456789abcdef")
 
@@ -167,7 +167,7 @@ class MangadexMangaExtractor(MangadexExtractor):
 class MangadexFeedExtractor(MangadexExtractor):
     """Extractor for chapters from your Updates Feed"""
     subcategory = "feed"
-    pattern = rf"{BASE_PATTERN}/titles?/feed$()"
+    pattern = BASE_PATTERN + r"/titles?/feed$()"
     example = "https://mangadex.org/title/feed"
 
     def chapters(self):
@@ -177,7 +177,7 @@ class MangadexFeedExtractor(MangadexExtractor):
 class MangadexFollowingExtractor(MangadexExtractor):
     """Extractor for followed manga from your Library"""
     subcategory = "following"
-    pattern = rf"{BASE_PATTERN}/titles?/follows(?:\?([^#]+))?$"
+    pattern = BASE_PATTERN + r"/titles?/follows(?:\?([^#]+))?$"
     example = "https://mangadex.org/title/follows"
 
     items = MangadexExtractor._items_manga
@@ -189,8 +189,8 @@ class MangadexFollowingExtractor(MangadexExtractor):
 class MangadexListExtractor(MangadexExtractor):
     """Extractor for mangadex MDLists"""
     subcategory = "list"
-    pattern = (rf"{BASE_PATTERN}"
-               rf"/list/([0-9a-f-]+)(?:/[^/?#]*)?(?:\?tab=(\w+))?")
+    pattern = (BASE_PATTERN +
+               r"/list/([0-9a-f-]+)(?:/[^/?#]*)?(?:\?tab=(\w+))?")
     example = ("https://mangadex.org/list"
                "/01234567-89ab-cdef-0123-456789abcdef/NAME")
 
@@ -215,7 +215,7 @@ class MangadexListExtractor(MangadexExtractor):
 class MangadexAuthorExtractor(MangadexExtractor):
     """Extractor for mangadex authors"""
     subcategory = "author"
-    pattern = rf"{BASE_PATTERN}/author/([0-9a-f-]+)"
+    pattern = BASE_PATTERN + r"/author/([0-9a-f-]+)"
     example = ("https://mangadex.org/author"
                "/01234567-89ab-cdef-0123-456789abcdef/NAME")
 
diff --git a/gallery_dl/extractor/mangafire.py b/gallery_dl/extractor/mangafire.py
index 5ccb7323..ac8b3970 100644
--- a/gallery_dl/extractor/mangafire.py
+++ b/gallery_dl/extractor/mangafire.py
@@ -31,8 +31,8 @@ class MangafireChapterExtractor(MangafireBase, ChapterExtractor):
         "{page:>03}.{extension}")
     archive_fmt = (
         "{manga_id}_{chapter_id}_{page}")
-    pattern = (rf"{BASE_PATTERN}/read/([\w-]+\.(\w+))/([\w-]+)"
-               rf"/((chapter|volume)-\d+(?:\D.*)?)")
+    pattern = (BASE_PATTERN + r"/read/([\w-]+\.(\w+))/([\w-]+)"
+               r"/((chapter|volume)-\d+(?:\D.*)?)")
     example = "https://mangafire.to/read/MANGA.ID/LANG/chapter-123"
 
     def metadata(self, _):
@@ -64,7 +64,7 @@ class MangafireChapterExtractor(MangafireBase, ChapterExtractor):
 class MangafireMangaExtractor(MangafireBase, MangaExtractor):
     """Extractor for mangafire manga"""
     chapterclass = MangafireChapterExtractor
-    pattern = rf"{BASE_PATTERN}/manga/([\w-]+)\.(\w+)"
+    pattern = BASE_PATTERN + r"/manga/([\w-]+)\.(\w+)"
     example = "https://mangafire.to/manga/MANGA.ID"
 
     def chapters(self, page):
diff --git a/gallery_dl/extractor/mangareader.py b/gallery_dl/extractor/mangareader.py
index eb53998e..21a59bdf 100644
--- a/gallery_dl/extractor/mangareader.py
+++ b/gallery_dl/extractor/mangareader.py
@@ -31,8 +31,8 @@ class MangareaderChapterExtractor(MangareaderBase, ChapterExtractor):
         "{page:>03}.{extension}")
     archive_fmt = (
         "{manga_id}_{chapter_id}_{page}")
-    pattern = (rf"{BASE_PATTERN}/read/([\w-]+-\d+)/([^/?#]+)"
-               rf"/(chapter|volume)-(\d+[^/?#]*)")
+    pattern = (BASE_PATTERN + r"/read/([\w-]+-\d+)/([^/?#]+)"
+               r"/(chapter|volume)-(\d+[^/?#]*)")
     example = "https://mangareader.to/read/MANGA-123/LANG/chapter-123"
 
     def metadata(self, _):
@@ -81,7 +81,7 @@ class MangareaderChapterExtractor(MangareaderBase, ChapterExtractor):
 class MangareaderMangaExtractor(MangareaderBase, MangaExtractor):
     """Extractor for mangareader manga"""
     chapterclass = MangareaderChapterExtractor
-    pattern = rf"{BASE_PATTERN}/([\w-]+-\d+)"
+    pattern = BASE_PATTERN + r"/([\w-]+-\d+)"
     example = "https://mangareader.to/MANGA-123"
 
     def chapters(self, page):
diff --git a/gallery_dl/extractor/mangataro.py b/gallery_dl/extractor/mangataro.py
index 029bc2e9..089d0827 100644
--- a/gallery_dl/extractor/mangataro.py
+++ b/gallery_dl/extractor/mangataro.py
@@ -23,7 +23,7 @@ class MangataroBase():
 
 class MangataroChapterExtractor(MangataroBase, ChapterExtractor):
     """Extractor for mangataro manga chapters"""
-    pattern = rf"{BASE_PATTERN}(/read/([^/?#]+)/(?:[^/?#]*-)?(\d+))"
+    pattern = BASE_PATTERN + r"(/read/([^/?#]+)/(?:[^/?#]*-)?(\d+))"
     example = "https://mangataro.org/read/MANGA/ch123-12345"
 
     def metadata(self, page):
@@ -59,7 +59,7 @@ class MangataroChapterExtractor(MangataroBase, ChapterExtractor):
 class MangataroMangaExtractor(MangataroBase, MangaExtractor):
     """Extractor for mangataro manga"""
     chapterclass = MangataroChapterExtractor
-    pattern = rf"{BASE_PATTERN}(/manga/([^/?#]+))"
+    pattern = BASE_PATTERN + r"(/manga/([^/?#]+))"
     example = "https://mangataro.org/manga/MANGA"
 
     def chapters(self, page):
diff --git a/gallery_dl/extractor/myhentaigallery.py b/gallery_dl/extractor/myhentaigallery.py
index 936f857a..b94a73f4 100644
--- a/gallery_dl/extractor/myhentaigallery.py
+++ b/gallery_dl/extractor/myhentaigallery.py
@@ -20,7 +20,7 @@ class MyhentaigalleryBase():
 class MyhentaigalleryGalleryExtractor(MyhentaigalleryBase, GalleryExtractor):
     """Extractor for image galleries from myhentaigallery.com"""
     directory_fmt = ("{category}", "{gallery_id} {artist:?[/] /J, }{title}")
-    pattern = rf"{BASE_PATTERN}/g(?:allery/(?:thumbnails|show))?/(\d+)"
+    pattern = BASE_PATTERN + r"/g(?:allery/(?:thumbnails|show))?/(\d+)"
     example = "https://myhentaigallery.com/g/12345"
 
     def __init__(self, match):
@@ -62,7 +62,7 @@ class MyhentaigalleryGalleryExtractor(MyhentaigalleryBase, GalleryExtractor):
 class MyhentaigalleryTagExtractor(MyhentaigalleryBase, Extractor):
     """Extractor for myhentaigallery tag searches"""
     subcategory = "tag"
-    pattern = rf"{BASE_PATTERN}(/g/(artist|category|group|parody)/(\d+).*)"
+    pattern = BASE_PATTERN + r"(/g/(artist|category|group|parody)/(\d+).*)"
     example = "https://myhentaigallery.com/g/category/123"
 
     def items(self):
diff --git a/gallery_dl/extractor/poipiku.py b/gallery_dl/extractor/poipiku.py
index c3aaabad..641bf713 100644
--- a/gallery_dl/extractor/poipiku.py
+++ b/gallery_dl/extractor/poipiku.py
@@ -176,8 +176,8 @@ class PoipikuExtractor(Extractor):
 class PoipikuUserExtractor(PoipikuExtractor):
     """Extractor for posts from a poipiku user"""
     subcategory = "user"
-    pattern = (rf"{BASE_PATTERN}/(?:IllustListPcV\.jsp\?PG=(\d+)&ID=)?"
-               rf"(\d+)/?(?:$|[?&#])")
+    pattern = (BASE_PATTERN + r"/(?:IllustListPcV\.jsp\?PG=(\d+)&ID=)?"
+               r"(\d+)/?(?:$|[?&#])")
     example = "https://poipiku.com/12345/"
 
     def posts(self):
@@ -207,7 +207,7 @@ class PoipikuUserExtractor(PoipikuExtractor):
 class PoipikuPostExtractor(PoipikuExtractor):
     """Extractor for a poipiku post"""
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/(\d+)/(\d+)"
+    pattern = BASE_PATTERN + r"/(\d+)/(\d+)"
     example = "https://poipiku.com/12345/12345.html"
 
     def posts(self):
diff --git a/gallery_dl/extractor/pornpics.py b/gallery_dl/extractor/pornpics.py
index 4f8e695d..0bcd7f4a 100644
--- a/gallery_dl/extractor/pornpics.py
+++ b/gallery_dl/extractor/pornpics.py
@@ -125,8 +125,8 @@ class PornpicsListingExtractor(PornpicsExtractor):
     and use single quotes in HTML, unlike category pages.
     """
     subcategory = "listing"
-    pattern = (rf"{BASE_PATTERN}"
-               rf"/(popular|recent|rating|likes|views|comments)/?$")
+    pattern = (BASE_PATTERN +
+               r"/(popular|recent|rating|likes|views|comments)/?$")
     example = "https://www.pornpics.com/popular/"
 
     def galleries(self):
@@ -142,7 +142,7 @@ class PornpicsListingExtractor(PornpicsExtractor):
 class PornpicsCategoryExtractor(PornpicsExtractor):
     """Extractor for galleries from pornpics categories"""
     subcategory = "category"
-    pattern = rf"{BASE_PATTERN}/([^/?#]+)/?$"
+    pattern = BASE_PATTERN + r"/([^/?#]+)/?$"
     example = "https://www.pornpics.com/ass/"
 
     def galleries(self):
diff --git a/gallery_dl/extractor/s3ndpics.py b/gallery_dl/extractor/s3ndpics.py
index 9201a3f2..39a30d08 100644
--- a/gallery_dl/extractor/s3ndpics.py
+++ b/gallery_dl/extractor/s3ndpics.py
@@ -59,7 +59,7 @@ class S3ndpicsExtractor(Extractor):
 
 class S3ndpicsPostExtractor(S3ndpicsExtractor):
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/post/([0-9a-f]+)"
+    pattern = BASE_PATTERN + r"/post/([0-9a-f]+)"
     example = "https://s3nd.pics/post/0123456789abcdef01234567"
 
     def posts(self):
@@ -69,7 +69,7 @@ class S3ndpicsPostExtractor(S3ndpicsExtractor):
 
 class S3ndpicsUserExtractor(S3ndpicsExtractor):
     subcategory = "user"
-    pattern = rf"{BASE_PATTERN}/user/(\w+)"
+    pattern = BASE_PATTERN + r"/user/(\w+)"
     example = "https://s3nd.pics/user/USER"
 
     def posts(self):
@@ -87,7 +87,7 @@ class S3ndpicsUserExtractor(S3ndpicsExtractor):
 
 class S3ndpicsSearchExtractor(S3ndpicsExtractor):
     subcategory = "search"
-    pattern = rf"{BASE_PATTERN}/search/?\?([^#]+)"
+    pattern = BASE_PATTERN + r"/search/?\?([^#]+)"
     example = "https://s3nd.pics/search?QUERY"
 
     def posts(self):
diff --git a/gallery_dl/extractor/schalenetwork.py b/gallery_dl/extractor/schalenetwork.py
index bbbb9da4..26d0cc96 100644
--- a/gallery_dl/extractor/schalenetwork.py
+++ b/gallery_dl/extractor/schalenetwork.py
@@ -98,7 +98,7 @@ class SchalenetworkGalleryExtractor(SchalenetworkExtractor, GalleryExtractor):
     directory_fmt = ("{category}", "{id} {title}")
     archive_fmt = "{id}_{num}"
     request_interval = 0.0
-    pattern = rf"{BASE_PATTERN}/(?:g|reader)/(\d+)/(\w+)"
+    pattern = BASE_PATTERN + r"/(?:g|reader)/(\d+)/(\w+)"
     example = "https://niyaniya.moe/g/12345/67890abcde/"
 
     TAG_TYPES = {
@@ -227,7 +227,7 @@ class SchalenetworkGalleryExtractor(SchalenetworkExtractor, GalleryExtractor):
 class SchalenetworkSearchExtractor(SchalenetworkExtractor):
     """Extractor for schale.network search results"""
     subcategory = "search"
-    pattern = rf"{BASE_PATTERN}/(?:tag/([^/?#]+)|browse)?(?:/?\?([^#]*))?$"
+    pattern = BASE_PATTERN + r"/(?:tag/([^/?#]+)|browse)?(?:/?\?([^#]*))?$"
     example = "https://niyaniya.moe/browse?s=QUERY"
 
     def items(self):
@@ -252,7 +252,7 @@ class SchalenetworkSearchExtractor(SchalenetworkExtractor):
 class SchalenetworkFavoriteExtractor(SchalenetworkExtractor):
     """Extractor for schale.network favorites"""
     subcategory = "favorite"
-    pattern = rf"{BASE_PATTERN}/favorites(?:\?([^#]*))?"
+    pattern = BASE_PATTERN + r"/favorites(?:\?([^#]*))?"
     example = "https://niyaniya.moe/favorites"
 
     def items(self):
diff --git a/gallery_dl/extractor/sexcom.py b/gallery_dl/extractor/sexcom.py
index a667eec7..5fdbae47 100644
--- a/gallery_dl/extractor/sexcom.py
+++ b/gallery_dl/extractor/sexcom.py
@@ -273,7 +273,7 @@ class SexcomFeedExtractor(SexcomExtractor):
     """Extractor for pins from your account's main feed on www.sex.com"""
     subcategory = "feed"
     directory_fmt = ("{category}", "feed")
-    pattern = rf"{BASE_PATTERN}/feed"
+    pattern = BASE_PATTERN + r"/feed"
     example = "https://www.sex.com/feed/"
 
     def metadata(self):
diff --git a/gallery_dl/extractor/sizebooru.py b/gallery_dl/extractor/sizebooru.py
index 00002b84..3b61747a 100644
--- a/gallery_dl/extractor/sizebooru.py
+++ b/gallery_dl/extractor/sizebooru.py
@@ -98,7 +98,7 @@ class SizebooruExtractor(BooruExtractor):
 class SizebooruPostExtractor(SizebooruExtractor):
     """Extractor for sizebooru posts"""
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/Details/(\d+)"
+    pattern = BASE_PATTERN + r"/Details/(\d+)"
     example = "https://sizebooru.com/Details/12345"
 
     def posts(self):
@@ -109,7 +109,7 @@ class SizebooruTagExtractor(SizebooruExtractor):
     """Extractor for sizebooru tag searches"""
     subcategory = "tag"
     directory_fmt = ("{category}", "{search_tags}")
-    pattern = rf"{BASE_PATTERN}/Search/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/Search/([^/?#]+)"
     example = "https://sizebooru.com/Search/TAG"
 
     def posts(self):
@@ -122,7 +122,7 @@ class SizebooruGalleryExtractor(SizebooruExtractor):
     """Extractor for sizebooru galleries"""
     subcategory = "gallery"
     directory_fmt = ("{category}", "{gallery_name} ({gallery_id})")
-    pattern = rf"{BASE_PATTERN}/Galleries/List/(\d+)"
+    pattern = BASE_PATTERN + r"/Galleries/List/(\d+)"
     example = "https://sizebooru.com/Galleries/List/123"
 
     def posts(self):
@@ -140,7 +140,7 @@ class SizebooruUserExtractor(SizebooruExtractor):
     """Extractor for a sizebooru user's uploads"""
     subcategory = "user"
     directory_fmt = ("{category}", "Uploads {user}")
-    pattern = rf"{BASE_PATTERN}/Profile/Uploads/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/Profile/Uploads/([^/?#]+)"
     example = "https://sizebooru.com/Profile/Uploads/USER"
 
     def posts(self):
@@ -153,7 +153,7 @@ class SizebooruFavoriteExtractor(SizebooruExtractor):
     """Extractor for a sizebooru user's favorites"""
     subcategory = "favorite"
     directory_fmt = ("{category}", "Favorites {user}")
-    pattern = rf"{BASE_PATTERN}/Profile/Favorites/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/Profile/Favorites/([^/?#]+)"
     example = "https://sizebooru.com/Profile/Favorites/USER"
 
     def posts(self):
diff --git a/gallery_dl/extractor/thehentaiworld.py b/gallery_dl/extractor/thehentaiworld.py
index 773f3003..4c207d67 100644
--- a/gallery_dl/extractor/thehentaiworld.py
+++ b/gallery_dl/extractor/thehentaiworld.py
@@ -116,7 +116,7 @@ class ThehentaiworldTagExtractor(ThehentaiworldExtractor):
     page_start = 1
     post_start = 0
     directory_fmt = ("{category}", "{search_tags}")
-    pattern = rf"{BASE_PATTERN}/tag/([^/?#]+)"
+    pattern = BASE_PATTERN + r"/tag/([^/?#]+)"
     example = "https://thehentaiworld.com/tag/TAG/"
 
     def posts(self):
@@ -132,8 +132,8 @@ class ThehentaiworldTagExtractor(ThehentaiworldExtractor):
 
 class ThehentaiworldPostExtractor(ThehentaiworldExtractor):
     subcategory = "post"
-    pattern = (rf"{BASE_PATTERN}("
-               rf"/(?:video|(?:[\w-]+-)?hentai-image)s/([^/?#]+))")
+    pattern = (BASE_PATTERN +
+               r"(/(?:video|(?:[\w-]+-)?hentai-image)s/([^/?#]+))")
     example = "https://thehentaiworld.com/hentai-images/SLUG/"
 
     def posts(self):
diff --git a/gallery_dl/extractor/tungsten.py b/gallery_dl/extractor/tungsten.py
index 67c0b508..8f2b55d1 100644
--- a/gallery_dl/extractor/tungsten.py
+++ b/gallery_dl/extractor/tungsten.py
@@ -52,7 +52,7 @@ class TungstenExtractor(Extractor):
 
 class TungstenPostExtractor(TungstenExtractor):
     subcategory = "post"
-    pattern = rf"{BASE_PATTERN}/post/(\w+)"
+    pattern = BASE_PATTERN + r"/post/(\w+)"
     example = "https://tungsten.run/post/AbCdEfGhIjKlMnOp"
 
     def posts(self):
@@ -64,7 +64,7 @@ class TungstenPostExtractor(TungstenExtractor):
 
 class TungstenModelExtractor(TungstenExtractor):
     subcategory = "model"
-    pattern = rf"{BASE_PATTERN}/model/(\w+)(?:/?\?model_version=(\w+))?"
+    pattern = BASE_PATTERN + r"/model/(\w+)(?:/?\?model_version=(\w+))?"
     example = "https://tungsten.run/model/AbCdEfGhIjKlM"
 
     def posts(self):
@@ -87,7 +87,7 @@ class TungstenModelExtractor(TungstenExtractor):
 
 class TungstenUserExtractor(TungstenExtractor):
     subcategory = "user"
-    pattern = rf"{BASE_PATTERN}/user/([^/?#]+)(?:/posts)?/?(?:\?([^#]+))?"
+    pattern = BASE_PATTERN + r"/user/([^/?#]+)(?:/posts)?/?(?:\?([^#]+))?"
     example = "https://tungsten.run/user/USER"
 
     def posts(self):
diff --git a/gallery_dl/extractor/twitter.py b/gallery_dl/extractor/twitter.py
index 2c41f35f..801c5222 100644
--- a/gallery_dl/extractor/twitter.py
+++ b/gallery_dl/extractor/twitter.py
@@ -16,7 +16,7 @@ import random
 
 BASE_PATTERN = (r"(?:https?://)?(?:www\.|mobile\.)?"
                 r"(?:(?:[fv]x)?twitter|(?:fix(?:up|v))?x)\.com")
-USER_PATTERN = rf"{BASE_PATTERN}/([^/?#]+)"
+USER_PATTERN = BASE_PATTERN + r"/([^/?#]+)"
 
 
 class TwitterExtractor(Extractor):
@@ -749,7 +749,7 @@ class TwitterUserExtractor(Dispatch, TwitterExtractor):
 class TwitterTimelineExtractor(TwitterExtractor):
     """Extractor for a Twitter user timeline"""
     subcategory = "timeline"
-    pattern = rf"{USER_PATTERN}/timeline(?!\w)"
+    pattern = USER_PATTERN + r"/timeline(?!\w)"
     example = "https://x.com/USER/timeline"
 
     def _init_cursor(self):
@@ -846,7 +846,7 @@ class TwitterTimelineExtractor(TwitterExtractor):
 class TwitterTweetsExtractor(TwitterExtractor):
     """Extractor for Tweets from a user's Tweets timeline"""
     subcategory = "tweets"
-    pattern = rf"{USER_PATTERN}/tweets(?!\w)"
+    pattern = USER_PATTERN + r"/tweets(?!\w)"
     example = "https://x.com/USER/tweets"
 
     def tweets(self):
@@ -856,7 +856,7 @@ class TwitterTweetsExtractor(TwitterExtractor):
 class TwitterRepliesExtractor(TwitterExtractor):
     """Extractor for Tweets from a user's timeline including replies"""
     subcategory = "replies"
-    pattern = rf"{USER_PATTERN}/with_replies(?!\w)"
+    pattern = USER_PATTERN + r"/with_replies(?!\w)"
     example = "https://x.com/USER/with_replies"
 
     def tweets(self):
@@ -866,7 +866,7 @@ class TwitterRepliesExtractor(TwitterExtractor):
 class TwitterHighlightsExtractor(TwitterExtractor):
     """Extractor for Tweets from a user's highlights timeline"""
     subcategory = "highlights"
-    pattern = rf"{USER_PATTERN}/highlights(?!\w)"
+    pattern = USER_PATTERN + r"/highlights(?!\w)"
     example = "https://x.com/USER/highlights"
 
     def tweets(self):
@@ -876,7 +876,7 @@ class TwitterHighlightsExtractor(TwitterExtractor):
 class TwitterMediaExtractor(TwitterExtractor):
     """Extractor for Tweets from a user's Media timeline"""
     subcategory = "media"
-    pattern = rf"{USER_PATTERN}/media(?!\w)"
+    pattern = USER_PATTERN + r"/media(?!\w)"
     example = "https://x.com/USER/media"
 
     def tweets(self):
@@ -886,7 +886,7 @@ class TwitterMediaExtractor(TwitterExtractor):
 class TwitterLikesExtractor(TwitterExtractor):
     """Extractor for liked tweets"""
     subcategory = "likes"
-    pattern = rf"{USER_PATTERN}/likes(?!\w)"
+    pattern = USER_PATTERN + r"/likes(?!\w)"
     example = "https://x.com/USER/likes"
 
     def metadata(self):
@@ -936,7 +936,7 @@ class TwitterListMembersExtractor(TwitterExtractor):
 class TwitterFollowingExtractor(TwitterExtractor):
     """Extractor for followed users"""
     subcategory = "following"
-    pattern = rf"{USER_PATTERN}/following(?!\w)"
+    pattern = USER_PATTERN + r"/following(?!\w)"
     example = "https://x.com/USER/following"
 
     def items(self):
@@ -947,7 +947,7 @@ class TwitterFollowingExtractor(TwitterExtractor):
 class TwitterFollowersExtractor(TwitterExtractor):
     """Extractor for a user's followers"""
     subcategory = "followers"
-    pattern = rf"{USER_PATTERN}/followers(?!\w)"
+    pattern = USER_PATTERN + r"/followers(?!\w)"
     example = "https://x.com/USER/followers"
 
     def items(self):
@@ -1093,7 +1093,7 @@ class TwitterQuotesExtractor(TwitterExtractor):
 class TwitterInfoExtractor(TwitterExtractor):
     """Extractor for a user's profile data"""
     subcategory = "info"
-    pattern = rf"{USER_PATTERN}/info"
+    pattern = USER_PATTERN + r"/info"
     example = "https://x.com/USER/info"
 
     def items(self):
@@ -1112,7 +1112,7 @@ class TwitterAvatarExtractor(TwitterExtractor):
     subcategory = "avatar"
     filename_fmt = "avatar {date}.{extension}"
     archive_fmt = "AV_{user[id]}_{date}"
-    pattern = rf"{USER_PATTERN}/photo"
+    pattern = USER_PATTERN + r"/photo"
     example = "https://x.com/USER/photo"
 
     def tweets(self):
@@ -1134,7 +1134,7 @@ class TwitterBackgroundExtractor(TwitterExtractor):
     subcategory = "background"
     filename_fmt = "background {date}.{extension}"
     archive_fmt = "BG_{user[id]}_{date}"
-    pattern = rf"{USER_PATTERN}/header_photo"
+    pattern = USER_PATTERN + r"/header_photo"
     example = "https://x.com/USER/header_photo"
 
     def tweets(self):
diff --git a/gallery_dl/extractor/weibo.py b/gallery_dl/extractor/weibo.py
index abec0f76..16c76ac6 100644
--- a/gallery_dl/extractor/weibo.py
+++ b/gallery_dl/extractor/weibo.py
@@ -14,7 +14,7 @@ from ..cache import cache
 import random
 
 BASE_PATTERN = r"(?:https?://)?(?:www\.|m\.)?weibo\.c(?:om|n)"
-USER_PATTERN = rf"{BASE_PATTERN}/(?:(u|n|p(?:rofile)?)/)?([^/?#]+)(?:/home)?"
+USER_PATTERN = BASE_PATTERN + r"/(?:(u|n|p(?:rofile)?)/)?([^/?#]+)(?:/home)?"
 
 
 class WeiboExtractor(Extractor):
@@ -296,7 +296,7 @@ class WeiboExtractor(Extractor):
 class WeiboUserExtractor(WeiboExtractor):
     """Extractor for weibo user profiles"""
     subcategory = "user"
-    pattern = rf"{USER_PATTERN}(?:$|#)"
+    pattern = USER_PATTERN + r"(?:$|#)"
     example = "https://weibo.com/USER"
 
     # do NOT override 'initialize()'
@@ -318,7 +318,7 @@ class WeiboUserExtractor(WeiboExtractor):
 class WeiboHomeExtractor(WeiboExtractor):
     """Extractor for weibo 'home' listings"""
     subcategory = "home"
-    pattern = rf"{USER_PATTERN}\?tabtype=home"
+    pattern = USER_PATTERN + r"\?tabtype=home"
     example = "https://weibo.com/USER?tabtype=home"
 
     def statuses(self):
@@ -330,7 +330,7 @@ class WeiboHomeExtractor(WeiboExtractor):
 class WeiboFeedExtractor(WeiboExtractor):
     """Extractor for weibo user feeds"""
     subcategory = "feed"
-    pattern = rf"{USER_PATTERN}\?tabtype=feed"
+    pattern = USER_PATTERN + r"\?tabtype=feed"
     example = "https://weibo.com/USER?tabtype=feed"
 
     def statuses(self):
@@ -344,7 +344,7 @@ class WeiboFeedExtractor(WeiboExtractor):
 class WeiboVideosExtractor(WeiboExtractor):
     """Extractor for weibo 'video' listings"""
     subcategory = "videos"
-    pattern = rf"{USER_PATTERN}\?tabtype=video"
+    pattern = USER_PATTERN + r"\?tabtype=video"
     example = "https://weibo.com/USER?tabtype=video"
 
     def statuses(self):
@@ -358,7 +358,7 @@ class WeiboVideosExtractor(WeiboExtractor):
 class WeiboNewvideoExtractor(WeiboExtractor):
     """Extractor for weibo 'newVideo' listings"""
     subcategory = "newvideo"
-    pattern = rf"{USER_PATTERN}\?tabtype=newVideo"
+    pattern = USER_PATTERN + r"\?tabtype=newVideo"
     example = "https://weibo.com/USER?tabtype=newVideo"
 
     def statuses(self):
@@ -370,7 +370,7 @@ class WeiboNewvideoExtractor(WeiboExtractor):
 class WeiboArticleExtractor(WeiboExtractor):
     """Extractor for weibo 'article' listings"""
     subcategory = "article"
-    pattern = rf"{USER_PATTERN}\?tabtype=article"
+    pattern = USER_PATTERN + r"\?tabtype=article"
     example = "https://weibo.com/USER?tabtype=article"
 
     def statuses(self):
@@ -382,7 +382,7 @@ class WeiboArticleExtractor(WeiboExtractor):
 class WeiboAlbumExtractor(WeiboExtractor):
     """Extractor for weibo 'album' listings"""
     subcategory = "album"
-    pattern = rf"{USER_PATTERN}\?tabtype=album"
+    pattern = USER_PATTERN + r"\?tabtype=album"
     example = "https://weibo.com/USER?tabtype=album"
 
     def statuses(self):
@@ -404,7 +404,7 @@ class WeiboAlbumExtractor(WeiboExtractor):
 class WeiboStatusExtractor(WeiboExtractor):
     """Extractor for a weibo status"""
     subcategory = "status"
-    pattern = rf"{BASE_PATTERN}/(detail|status|\d+)/(\w+)"
+    pattern = BASE_PATTERN + r"/(detail|status|\d+)/(\w+)"
     example = "https://weibo.com/detail/12345"
 
     def statuses(self):
diff --git a/gallery_dl/extractor/xenforo.py b/gallery_dl/extractor/xenforo.py
index d8536b01..fb68332f 100644
--- a/gallery_dl/extractor/xenforo.py
+++ b/gallery_dl/extractor/xenforo.py
@@ -282,8 +282,8 @@ BASE_PATTERN = XenforoExtractor.update({
 
 class XenforoPostExtractor(XenforoExtractor):
     subcategory = "post"
-    pattern = (rf"{BASE_PATTERN}(/(?:index\.php\?)?threads"
-               rf"/[^/?#]+/post-|/posts/)(\d+)")
+    pattern = (BASE_PATTERN + r"(/(?:index\.php\?)?threads"
+               r"/[^/?#]+/post-|/posts/)(\d+)")
     example = "https://simpcity.cr/threads/TITLE.12345/post-54321"
 
     def posts(self):
@@ -303,8 +303,8 @@ class XenforoPostExtractor(XenforoExtractor):
 
 class XenforoThreadExtractor(XenforoExtractor):
     subcategory = "thread"
-    pattern = (rf"{BASE_PATTERN}(/(?:index\.php\?)?threads"
-               rf"/(?:[^/?#]+\.)?\d+)(?:/page-(\d+))?")
+    pattern = (BASE_PATTERN + r"(/(?:index\.php\?)?threads"
+               r"/(?:[^/?#]+\.)?\d+)(?:/page-(\d+))?")
     example = "https://simpcity.cr/threads/TITLE.12345/"
 
     def posts(self):
@@ -332,8 +332,8 @@ class XenforoThreadExtractor(XenforoExtractor):
 
 class XenforoForumExtractor(XenforoExtractor):
     subcategory = "forum"
-    pattern = (rf"{BASE_PATTERN}(/(?:index\.php\?)?forums"
-               rf"/(?:[^/?#]+\.)?[^/?#]+)(?:/page-(\d+))?")
+    pattern = (BASE_PATTERN + r"(/(?:index\.php\?)?forums"
+               r"/(?:[^/?#]+\.)?[^/?#]+)(?:/page-(\d+))?")
     example = "https://simpcity.cr/forums/TITLE.123/"
 
     def items(self):