diff --git a/.pymon b/.pymon
new file mode 100644
index 00000000..dd492ecd
Binary files /dev/null and b/.pymon differ
diff --git a/isort/deprecated/finders.py b/isort/deprecated/finders.py
index e80a59a0..d82947b2 100644
--- a/isort/deprecated/finders.py
+++ b/isort/deprecated/finders.py
@@ -63,7 +63,7 @@ def find(self, module_name: str) -> Optional[str]:
             # Ensure all forced_separate patterns will match to end of string
             path_glob = forced_separate
             if not forced_separate.endswith("*"):
-                path_glob = "%s*" % forced_separate
+                path_glob = f"{forced_separate}*"
 
             if fnmatch(module_name, path_glob) or fnmatch(module_name, "." + path_glob):
                 return forced_separate
diff --git a/isort/main.py b/isort/main.py
index 26310048..bfb19fce 100644
--- a/isort/main.py
+++ b/isort/main.py
@@ -967,7 +967,7 @@ def _preconvert(item: Any) -> Union[str, List[Any]]:
         return str(item)
     if callable(item) and hasattr(item, "__name__"):
         return str(item.__name__)
-    raise TypeError("Unserializable object {} of type {}".format(item, type(item)))
+    raise TypeError(f"Unserializable object {item} of type {type(item)}")
 
 
 def identify_imports_main(
diff --git a/isort/place.py b/isort/place.py
index 47a68c78..8a972f50 100644
--- a/isort/place.py
+++ b/isort/place.py
@@ -34,7 +34,7 @@ def _forced_separate(name: str, config: Config) -> Optional[Tuple[str, str]]:
         # Ensure all forced_separate patterns will match to end of string
         path_glob = forced_separate
         if not forced_separate.endswith("*"):
-            path_glob = "%s*" % forced_separate
+            path_glob = f"{forced_separate}*"
 
         if fnmatch(name, path_glob) or fnmatch(name, "." + path_glob):
             return (forced_separate, f"Matched forced_separate ({forced_separate}) config value.")
diff --git a/isort/setuptools_commands.py b/isort/setuptools_commands.py
index d60deda6..e0538ffe 100644
--- a/isort/setuptools_commands.py
+++ b/isort/setuptools_commands.py
@@ -43,7 +43,7 @@ def distribution_files(self) -> Iterator[str]:
 
         if self.distribution.py_modules:
             for filename in self.distribution.py_modules:
-                yield "%s.py" % filename
+                yield f"{filename}.py"
         # Don't miss the setup.py file itself
         yield "setup.py"