diff --git a/gallery_dl/archive.py b/gallery_dl/archive.py
index edecb103..3df50116 100644
--- a/gallery_dl/archive.py
+++ b/gallery_dl/archive.py
@@ -41,7 +41,7 @@ def connect(path, prefix, format,
 
 
 def sanitize(name):
-    return '"' + name.replace('"', "_") + '"'
+    return f'''"{name.replace('"', '_')}"'''
 
 
 class DownloadArchive():
@@ -68,25 +68,25 @@ class DownloadArchive():
 
         table = "archive" if table is None else sanitize(table)
         self._stmt_select = (
-            "SELECT 1 "
-            "FROM " + table + " "
-            "WHERE entry=? "
-            "LIMIT 1")
+            f"SELECT 1 "
+            f"FROM {table} "
+            f"WHERE entry=? "
+            f"LIMIT 1")
         self._stmt_insert = (
-            "INSERT OR IGNORE INTO " + table + " "
-            "(entry) VALUES (?)")
+            f"INSERT OR IGNORE INTO {table} "
+            f"(entry) VALUES (?)")
 
         if pragma:
             for stmt in pragma:
-                cursor.execute("PRAGMA " + stmt)
+                cursor.execute(f"PRAGMA {stmt}")
 
         try:
-            cursor.execute("CREATE TABLE IF NOT EXISTS " + table + " "
-                           "(entry TEXT PRIMARY KEY) WITHOUT ROWID")
+            cursor.execute(f"CREATE TABLE IF NOT EXISTS {table} "
+                           f"(entry TEXT PRIMARY KEY) WITHOUT ROWID")
         except self._sqlite3.OperationalError:
             # fallback for missing WITHOUT ROWID support (#553)
-            cursor.execute("CREATE TABLE IF NOT EXISTS " + table + " "
-                           "(entry TEXT PRIMARY KEY)")
+            cursor.execute(f"CREATE TABLE IF NOT EXISTS {table} "
+                           f"(entry TEXT PRIMARY KEY)")
 
     def add(self, kwdict):
         """Add item described by 'kwdict' to archive"""
@@ -156,18 +156,18 @@ class DownloadArchivePostgresql():
 
         table = "archive" if table is None else sanitize(table)
         self._stmt_select = (
-            "SELECT true "
-            "FROM " + table + " "
-            "WHERE entry=%s "
-            "LIMIT 1")
+            f"SELECT true "
+            f"FROM {table} "
+            f"WHERE entry=%s "
+            f"LIMIT 1")
         self._stmt_insert = (
-            "INSERT INTO " + table + " (entry) "
-            "VALUES (%s) "
-            "ON CONFLICT DO NOTHING")
+            f"INSERT INTO {table} (entry) "
+            f"VALUES (%s) "
+            f"ON CONFLICT DO NOTHING")
 
         try:
-            cursor.execute("CREATE TABLE IF NOT EXISTS " + table + " "
-                           "(entry TEXT PRIMARY KEY)")
+            cursor.execute(f"CREATE TABLE IF NOT EXISTS {table} "
+                           f"(entry TEXT PRIMARY KEY)")
             con.commit()
         except Exception as exc:
             log.error("%s: %s when creating '%s' table: %s",
diff --git a/gallery_dl/job.py b/gallery_dl/job.py
index 12eeb4c0..132c5acd 100644
--- a/gallery_dl/job.py
+++ b/gallery_dl/job.py
@@ -853,7 +853,7 @@ class UrlJob(Job):
         stdout_write(url + "\n")
         if "_fallback" in kwdict:
             for url in kwdict["_fallback"]:
-                stdout_write("| " + url + "\n")
+                stdout_write(f"| {url}\n")
 
     def handle_queue(self, url, kwdict):
         if cls := kwdict.get("_extractor"):
diff --git a/gallery_dl/path.py b/gallery_dl/path.py
index 795564d5..71cba60b 100644
--- a/gallery_dl/path.py
+++ b/gallery_dl/path.py
@@ -122,7 +122,7 @@ class PathFormat():
             basedir = config("base-directory")
             sep = os.sep
             if basedir is None:
-                basedir = "." + sep + "gallery-dl" + sep
+                basedir = f".{sep}gallery-dl{sep}"
             elif basedir:
                 basedir = util.expand_path(basedir)
                 altsep = os.altsep
diff --git a/gallery_dl/transaction_id.py b/gallery_dl/transaction_id.py
index 915b7b3f..f8769d9a 100644
--- a/gallery_dl/transaction_id.py
+++ b/gallery_dl/transaction_id.py
@@ -65,8 +65,8 @@ class ClientTransaction():
 
     @cache(maxage=36500*86400, keyarg=1)
     def _extract_indices(self, ondemand_s, extractor):
-        url = ("https://abs.twimg.com/responsive-web/client-web"
-               "/ondemand.s." + ondemand_s + "a.js")
+        url = (f"https://abs.twimg.com/responsive-web/client-web"
+               f"/ondemand.s.{ondemand_s}a.js")
         page = extractor.request(url).text
         pattern = util.re_compile(r"\(\w\[(\d\d?)\],\s*16\)")
         return [int(i) for i in pattern.findall(page)]
diff --git a/gallery_dl/util.py b/gallery_dl/util.py
index 4027ac6f..45ffc9c3 100644
--- a/gallery_dl/util.py
+++ b/gallery_dl/util.py
@@ -512,15 +512,15 @@ def cookiestxt_store(fp, cookies):
             value = cookie.value
 
         domain = cookie.domain
-        fp.write("\t".join((
-            domain,
-            "TRUE" if domain and domain[0] == "." else "FALSE",
-            cookie.path,
-            "TRUE" if cookie.secure else "FALSE",
-            "0" if cookie.expires is None else str(cookie.expires),
-            name,
-            value + "\n",
-        )))
+        fp.write(
+            f"{domain}\t"
+            f"{'TRUE' if domain and domain[0] == '.' else 'FALSE'}\t"
+            f"{cookie.path}\t"
+            f"{'TRUE' if cookie.secure else 'FALSE'}\t"
+            f"{'0' if cookie.expires is None else str(cookie.expires)}\t"
+            f"{name}\t"
+            f"{value}\n"
+        )
 
 
 def code_to_language(code, default=None):