Replace % string formatting with f-string

tests/protocols/test_http.py

@@ -619,7 +619,8 @@ async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable
 async def test_http10_request(http_protocol_cls: HTTPProtocol):
     async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable):
         assert scope["type"] == "http"
-        content = "Version: %s" % scope["http_version"]
+        version = scope["http_version"]
+        content = f"Version: {version}"
         response = Response(content, media_type="text/plain")
         await response(scope, receive, send)
 

tests/response.py

@@ -33,5 +33,5 @@ def set_content_type(self):
         if self.media_type is not None and "content-type" not in self.headers:
             content_type = self.media_type
             if content_type.startswith("text/") and self.charset is not None:
-                content_type += "; charset=%s" % self.charset
+                content_type += f"; charset={self.charset}"
             self.headers["content-type"] = content_type

tests/test_cli.py

@@ -131,7 +131,7 @@ def test_cli_incomplete_app_parameter() -> None:
     result = runner.invoke(cli, ["tests.test_cli"])
 
     assert (
-        'Error loading ASGI app. Import string "tests.test_cli" ' 'must be in format "<module>:<attribute>".'
+        'Error loading ASGI app: Import string "tests.test_cli" must be in format "<module>:<attribute>".'
     ) in result.output
     assert result.exit_code == 1
 

tests/test_config.py

@@ -224,7 +224,7 @@ def test_app_unimportable_other(caplog: pytest.LogCaptureFixture) -> None:
         record.message for record in caplog.records if record.name == "uvicorn.error" and record.levelname == "ERROR"
     ]
     assert (
-        'Error loading ASGI app. Attribute "app" not found in module "tests.test_config".'  # noqa: E501
+        'Error loading ASGI app: Attribute "app" not found in module "tests.test_config".'  # noqa: E501
         == error_messages.pop(0)
     )
 

uvicorn/config.py

@@ -433,19 +433,19 @@ def load(self) -> None:
         try:
             self.loaded_app = import_from_string(self.app)
         except ImportFromStringError as exc:
-            logger.error("Error loading ASGI app. %s" % exc)
+            logger.exception("Error loading ASGI app: %s", exc)
             sys.exit(1)
 
         try:
             self.loaded_app = self.loaded_app()
         except TypeError as exc:
             if self.factory:
-                logger.error("Error loading ASGI app factory: %s", exc)
+                logger.exception("Error loading ASGI app factory: %s", exc)
                 sys.exit(1)
         else:
             if not self.factory:
                 logger.warning(
-                    "ASGI app factory detected. Using it, " "but please consider setting the --factory flag explicitly."
+                    "ASGI app factory detected. Using it, but please consider setting the --factory flag explicitly."
                 )
 
         if self.interface == "auto":

uvicorn/importer.py

@@ -12,23 +12,23 @@ def import_from_string(import_str: Any) -> Any:
 
     module_str, _, attrs_str = import_str.partition(":")
     if not module_str or not attrs_str:
-        message = 'Import string "{import_str}" must be in format "<module>:<attribute>".'
-        raise ImportFromStringError(message.format(import_str=import_str))
+        message = f'Import string "{import_str}" must be in format "<module>:<attribute>".'
+        raise ImportFromStringError(message)
 
     try:
         module = importlib.import_module(module_str)
     except ModuleNotFoundError as exc:
         if exc.name != module_str:
             raise exc from None
-        message = 'Could not import module "{module_str}".'
-        raise ImportFromStringError(message.format(module_str=module_str))
+        message = f'Could not import module "{module_str}".'
+        raise ImportFromStringError(message)
 
     instance = module
     try:
         for attr_str in attrs_str.split("."):
             instance = getattr(instance, attr_str)
     except AttributeError:
-        message = 'Attribute "{attrs_str}" not found in module "{module_str}".'
-        raise ImportFromStringError(message.format(attrs_str=attrs_str, module_str=module_str))
+        message = f'Attribute "{attrs_str}" not found in module "{module_str}".'
+        raise ImportFromStringError(message)
 
     return instance

uvicorn/middleware/wsgi.py

@@ -32,12 +32,13 @@ def build_environ(scope: HTTPScope, message: ASGIReceiveEvent, body: io.BytesIO)
     path_info = scope["path"].encode("utf8").decode("latin1")
     if path_info.startswith(script_name):
         path_info = path_info[len(script_name) :]
+    version = scope["http_version"]
     environ = {
         "REQUEST_METHOD": scope["method"],
         "SCRIPT_NAME": script_name,
         "PATH_INFO": path_info,
         "QUERY_STRING": scope["query_string"].decode("ascii"),
-        "SERVER_PROTOCOL": "HTTP/%s" % scope["http_version"],
+        "SERVER_PROTOCOL": f"HTTP/{version}",
         "wsgi.version": (1, 0),
         "wsgi.url_scheme": scope.get("scheme", "http"),
         "wsgi.input": body,
@@ -67,7 +68,8 @@ def build_environ(scope: HTTPScope, message: ASGIReceiveEvent, body: io.BytesIO)
         elif name_str == "content-type":
             corrected_name = "CONTENT_TYPE"
         else:
-            corrected_name = "HTTP_%s" % name_str.upper().replace("-", "_")
+            name_upper = name_str.upper().replace("-", "_")
+            corrected_name = f"HTTP_{name_upper}"
         # HTTPbis say only ASCII chars are allowed in headers, but we latin1
         # just in case
         value_str: str = value.decode("latin1")