diff --git a/kitty/fonts/core_text.py b/kitty/fonts/core_text.py
index 6718fc0f2..b9e4735b4 100644
--- a/kitty/fonts/core_text.py
+++ b/kitty/fonts/core_text.py
@@ -29,7 +29,7 @@ def create_font_map(all_fonts: Iterable[CoreTextFont]) -> FontMap:
         ps = (x['postscript_name'] or '').lower()
         ans['family_map'].setdefault(f, []).append(x)
         ans['ps_map'].setdefault(ps, []).append(x)
-        ans['full_map'].setdefault(f + ' ' + s, []).append(x)
+        ans['full_map'].setdefault(f'{f} {s}', []).append(x)
     return ans
 
 
@@ -45,7 +45,7 @@ def list_fonts() -> Generator[ListedFont, None, None]:
     for fd in coretext_all_fonts():
         f = fd['family']
         if f:
-            fn = (f + ' ' + (fd['style'] or '')).strip()
+            fn = f'{f} {fd.get("style", "")}'.strip()
             is_mono = bool(fd['monospace'])
             yield {'family': f, 'full_name': fn, 'postscript_name': fd['postscript_name'] or '', 'is_monospace': is_mono}
 
diff --git a/kitty/fonts/fontconfig.py b/kitty/fonts/fontconfig.py
index 763f8d333..01c3ba047 100644
--- a/kitty/fonts/fontconfig.py
+++ b/kitty/fonts/fontconfig.py
@@ -58,7 +58,7 @@ def list_fonts() -> Generator[ListedFont, None, None]:
             if fn_:
                 fn = str(fn_)
             else:
-                fn = (f + ' ' + str(fd.get('style', ''))).strip()
+                fn = f'{f} {fd.get("style", "")}'.strip()
             is_mono = fd.get('spacing') in ('MONO', 'DUAL')
             yield {'family': f, 'full_name': fn, 'postscript_name': str(fd.get('postscript_name', '')), 'is_monospace': is_mono}
 
diff --git a/kitty/fonts/list.py b/kitty/fonts/list.py
index 7cbc65209..e56343823 100644
--- a/kitty/fonts/list.py
+++ b/kitty/fonts/list.py
@@ -28,13 +28,13 @@ def main(argv: Sequence[str]) -> None:
     groups = create_family_groups()
     for k in sorted(groups, key=lambda x: x.lower()):
         if isatty:
-            print('\033[1;32m' + k + '\033[m')
+            print(f'\033[1;32m{k}\033[m')
         else:
             print(k)
         for f in sorted(groups[k], key=lambda x: x['full_name'].lower()):
             p = f['full_name']
             if isatty:
-                p = '\033[3m' + p + '\033[m'
+                p = f'\033[3m{p}\033[m'
             if psnames:
                 p += ' ({})'.format(f['postscript_name'])
             print('   ', p)
diff --git a/kitty/fonts/render.py b/kitty/fonts/render.py
index 500acb950..e617897a2 100644
--- a/kitty/fonts/render.py
+++ b/kitty/fonts/render.py
@@ -515,7 +515,7 @@ def test_fallback_font(qtext: Optional[str] = None, bold: bool = False, italic:
             try:
                 print(text, f)
             except UnicodeEncodeError:
-                sys.stdout.buffer.write((text + ' %s\n' % f).encode('utf-8'))
+                sys.stdout.buffer.write(f'{text} {f}\n'.encode('utf-8'))
 
 
 def showcase() -> None:
diff --git a/kitty/rc/send_text.py b/kitty/rc/send_text.py
index 1a658029c..8c623c197 100644
--- a/kitty/rc/send_text.py
+++ b/kitty/rc/send_text.py
@@ -107,20 +107,20 @@ Do not send text to the active window, even if it is one of the matched windows.
                         if '\x04' in decoded_data:
                             decoded_data = decoded_data[:decoded_data.index('\x04')]
                             keep_going = False
-                        ret['data'] = 'text:' + decoded_data
+                        ret['data'] = f'text:{decoded_data}'
                         yield ret
             else:
                 while True:
                     data = sys.stdin.buffer.read(limit)
                     if not data:
                         break
-                    ret['data'] = 'base64:' + base64.standard_b64encode(data).decode('ascii')
+                    ret['data'] = f'base64:{base64.standard_b64encode(data).decode("ascii")}'
                     yield ret
 
         def chunks(text: str) -> CmdGenerator:
             data = parse_send_text_bytes(text).decode('utf-8')
             while data:
-                ret['data'] = 'text:' + data[:limit]
+                ret['data'] = f'text:{data[:limit]}'
                 yield ret
                 data = data[limit:]
 
@@ -130,7 +130,7 @@ Do not send text to the active window, even if it is one of the matched windows.
                     data = f.read(limit)
                     if not data:
                         break
-                    ret['data'] = 'base64:' + base64.standard_b64encode(data).decode('ascii')
+                    ret['data'] = f'base64:{base64.standard_b64encode(data).decode("ascii")}'
                     yield ret
 
         sources = []