mypy: Enable no_implicit_optional

"Implicit-optional" mode is on by default, but that default is intended to change in the indefinite future (python/peps#689, python/typing#275). Go ahead and change to the future explicit use of Optional.

docs/httpserver.rst

@@ -5,7 +5,7 @@
 
    HTTP Server
    -----------
-   .. autoclass:: HTTPServer(request_callback: Union[httputil.HTTPServerConnectionDelegate, Callable[[httputil.HTTPServerRequest], None]], no_keep_alive: bool = False, xheaders: bool = False, ssl_options: Union[Dict[str, Any], ssl.SSLContext] = None, protocol: str = None, decompress_request: bool = False, chunk_size: int = None, max_header_size: int = None, idle_connection_timeout: float = None, body_timeout: float = None, max_body_size: int = None, max_buffer_size: int = None, trusted_downstream: List[str] = None)
+   .. autoclass:: HTTPServer(request_callback: Union[httputil.HTTPServerConnectionDelegate, Callable[[httputil.HTTPServerRequest], None]], no_keep_alive: bool = False, xheaders: bool = False, ssl_options: Union[Dict[str, Any], ssl.SSLContext] = None, protocol: Optional[str] = None, decompress_request: bool = False, chunk_size: Optional[int] = None, max_header_size: Optional[int] = None, idle_connection_timeout: Optional[float] = None, body_timeout: Optional[float] = None, max_body_size: Optional[int] = None, max_buffer_size: Optional[int] = None, trusted_downstream: Optional[List[str]] = None)
       :members:
 
       The public interface of this class is mostly inherited from

docs/web.rst

@@ -161,7 +161,7 @@
    Application configuration
    -------------------------
 
-   .. autoclass:: Application(handlers: List[Union[Rule, Tuple]] = None, default_host: str = None, transforms: List[Type[OutputTransform]] = None, **settings)
+   .. autoclass:: Application(handlers: Optional[List[Union[Rule, Tuple]]] = None, default_host: Optional[str] = None, transforms: Optional[List[Type[OutputTransform]]] = None, **settings)
 
       .. attribute:: settings
 

setup.cfg

@@ -3,6 +3,7 @@ license_file = LICENSE
 
 [mypy]
 python_version = 3.5
+no_implicit_optional = True
 
 [mypy-tornado.*,tornado.platform.*]
 disallow_untyped_defs = True

tornado/auth.py

@@ -87,7 +87,7 @@ class OpenIdMixin(object):
 
     def authenticate_redirect(
         self,
-        callback_uri: str = None,
+        callback_uri: Optional[str] = None,
         ax_attrs: List[str] = ["name", "email", "language", "username"],
     ) -> None:
         """Redirects to the authentication URL for this service.
@@ -114,7 +114,7 @@ def authenticate_redirect(
         handler.redirect(endpoint + "?" + urllib.parse.urlencode(args))
 
     async def get_authenticated_user(
-        self, http_client: httpclient.AsyncHTTPClient = None
+        self, http_client: Optional[httpclient.AsyncHTTPClient] = None
     ) -> Dict[str, Any]:
         """Fetches the authenticated user data upon redirect.
 
@@ -146,7 +146,10 @@ async def get_authenticated_user(
         return self._on_authentication_verified(resp)
 
     def _openid_args(
-        self, callback_uri: str, ax_attrs: Iterable[str] = [], oauth_scope: str = None
+        self,
+        callback_uri: str,
+        ax_attrs: Iterable[str] = [],
+        oauth_scope: Optional[str] = None,
     ) -> Dict[str, str]:
         handler = cast(RequestHandler, self)
         url = urllib.parse.urljoin(handler.request.full_url(), callback_uri)
@@ -286,9 +289,9 @@ class OAuthMixin(object):
 
     async def authorize_redirect(
         self,
-        callback_uri: str = None,
-        extra_params: Dict[str, Any] = None,
-        http_client: httpclient.AsyncHTTPClient = None,
+        callback_uri: Optional[str] = None,
+        extra_params: Optional[Dict[str, Any]] = None,
+        http_client: Optional[httpclient.AsyncHTTPClient] = None,
     ) -> None:
         """Redirects the user to obtain OAuth authorization for this service.
 
@@ -334,7 +337,7 @@ async def authorize_redirect(
         self._on_request_token(url, callback_uri, response)
 
     async def get_authenticated_user(
-        self, http_client: httpclient.AsyncHTTPClient = None
+        self, http_client: Optional[httpclient.AsyncHTTPClient] = None
     ) -> Dict[str, Any]:
         """Gets the OAuth authorized user and access token.
 
@@ -380,7 +383,9 @@ async def get_authenticated_user(
         return user
 
     def _oauth_request_token_url(
-        self, callback_uri: str = None, extra_params: Dict[str, Any] = None
+        self,
+        callback_uri: Optional[str] = None,
+        extra_params: Optional[Dict[str, Any]] = None,
     ) -> str:
         handler = cast(RequestHandler, self)
         consumer_token = self._oauth_consumer_token()
@@ -547,11 +552,11 @@ class OAuth2Mixin(object):
 
     def authorize_redirect(
         self,
-        redirect_uri: str = None,
-        client_id: str = None,
-        client_secret: str = None,
-        extra_params: Dict[str, Any] = None,
-        scope: str = None,
+        redirect_uri: Optional[str] = None,
+        client_id: Optional[str] = None,
+        client_secret: Optional[str] = None,
+        extra_params: Optional[Dict[str, Any]] = None,
+        scope: Optional[str] = None,
         response_type: str = "code",
     ) -> None:
         """Redirects the user to obtain OAuth authorization for this service.
@@ -582,11 +587,11 @@ def authorize_redirect(
 
     def _oauth_request_token_url(
         self,
-        redirect_uri: str = None,
-        client_id: str = None,
-        client_secret: str = None,
-        code: str = None,
-        extra_params: Dict[str, Any] = None,
+        redirect_uri: Optional[str] = None,
+        client_id: Optional[str] = None,
+        client_secret: Optional[str] = None,
+        code: Optional[str] = None,
+        extra_params: Optional[Dict[str, Any]] = None,
     ) -> str:
         url = self._OAUTH_ACCESS_TOKEN_URL  # type: ignore
         args = {}  # type: Dict[str, str]
@@ -605,8 +610,8 @@ def _oauth_request_token_url(
     async def oauth2_request(
         self,
         url: str,
-        access_token: str = None,
-        post_args: Dict[str, Any] = None,
+        access_token: Optional[str] = None,
+        post_args: Optional[Dict[str, Any]] = None,
         **args: Any
     ) -> Any:
         """Fetches the given URL auth an OAuth2 access token.
@@ -709,7 +714,7 @@ async def get(self):
     _OAUTH_NO_CALLBACKS = False
     _TWITTER_BASE_URL = "https://api.twitter.com/1.1"
 
-    async def authenticate_redirect(self, callback_uri: str = None) -> None:
+    async def authenticate_redirect(self, callback_uri: Optional[str] = None) -> None:
         """Just like `~OAuthMixin.authorize_redirect`, but
         auto-redirects if authorized.
 
@@ -735,7 +740,7 @@ async def twitter_request(
         self,
         path: str,
         access_token: Dict[str, Any],
-        post_args: Dict[str, Any] = None,
+        post_args: Optional[Dict[str, Any]] = None,
         **args: Any
     ) -> Any:
         """Fetches the given API path, e.g., ``statuses/user_timeline/btaylor``
@@ -930,7 +935,7 @@ async def get_authenticated_user(
         client_id: str,
         client_secret: str,
         code: str,
-        extra_fields: Dict[str, Any] = None,
+        extra_fields: Optional[Dict[str, Any]] = None,
     ) -> Optional[Dict[str, Any]]:
         """Handles the login for the Facebook user, returning a user object.
 
@@ -1034,8 +1039,8 @@ async def get(self):
     async def facebook_request(
         self,
         path: str,
-        access_token: str = None,
-        post_args: Dict[str, Any] = None,
+        access_token: Optional[str] = None,
+        post_args: Optional[Dict[str, Any]] = None,
         **args: Any
     ) -> Any:
         """Fetches the given relative API path, e.g., "/btaylor/picture"
@@ -1099,7 +1104,7 @@ def _oauth_signature(
     method: str,
     url: str,
     parameters: Dict[str, Any] = {},
-    token: Dict[str, Any] = None,
+    token: Optional[Dict[str, Any]] = None,
 ) -> bytes:
     """Calculates the HMAC-SHA1 OAuth signature for the given request.
 
@@ -1132,7 +1137,7 @@ def _oauth10a_signature(
     method: str,
     url: str,
     parameters: Dict[str, Any] = {},
-    token: Dict[str, Any] = None,
+    token: Optional[Dict[str, Any]] = None,
 ) -> bytes:
     """Calculates the HMAC-SHA1 OAuth 1.0a signature for the given request.
 

tornado/curl_httpclient.py

@@ -36,18 +36,18 @@
 )
 from tornado.log import app_log
 
-from typing import Dict, Any, Callable, Union
+from typing import Dict, Any, Callable, Union, Tuple, Optional
 import typing
 
 if typing.TYPE_CHECKING:
-    from typing import Deque, Tuple, Optional  # noqa: F401
+    from typing import Deque  # noqa: F401
 
 curl_log = logging.getLogger("tornado.curl_httpclient")
 
 
 class CurlAsyncHTTPClient(AsyncHTTPClient):
     def initialize(  # type: ignore
-        self, max_clients: int = 10, defaults: Dict[str, Any] = None
+        self, max_clients: int = 10, defaults: Optional[Dict[str, Any]] = None
     ) -> None:
         super(CurlAsyncHTTPClient, self).initialize(defaults=defaults)
         # Typeshed is incomplete for CurlMulti, so just use Any for now.
@@ -255,7 +255,10 @@ def _process_queue(self) -> None:
                 break
 
     def _finish(
-        self, curl: pycurl.Curl, curl_error: int = None, curl_message: str = None
+        self,
+        curl: pycurl.Curl,
+        curl_error: Optional[int] = None,
+        curl_message: Optional[str] = None,
     ) -> None:
         info = curl.info  # type: ignore
         curl.info = None  # type: ignore

tornado/http1connection.py

@@ -75,11 +75,11 @@ class HTTP1ConnectionParameters(object):
     def __init__(
         self,
         no_keep_alive: bool = False,
-        chunk_size: int = None,
-        max_header_size: int = None,
-        header_timeout: float = None,
-        max_body_size: int = None,
-        body_timeout: float = None,
+        chunk_size: Optional[int] = None,
+        max_header_size: Optional[int] = None,
+        header_timeout: Optional[float] = None,
+        max_body_size: Optional[int] = None,
+        body_timeout: Optional[float] = None,
         decompress: bool = False,
     ) -> None:
         """
@@ -113,8 +113,8 @@ def __init__(
         self,
         stream: iostream.IOStream,
         is_client: bool,
-        params: HTTP1ConnectionParameters = None,
-        context: object = None,
+        params: Optional[HTTP1ConnectionParameters] = None,
+        context: Optional[object] = None,
     ) -> None:
         """
         :arg stream: an `.IOStream`
@@ -377,7 +377,7 @@ def write_headers(
         self,
         start_line: Union[httputil.RequestStartLine, httputil.ResponseStartLine],
         headers: httputil.HTTPHeaders,
-        chunk: bytes = None,
+        chunk: Optional[bytes] = None,
     ) -> "Future[None]":
         """Implements `.HTTPConnection.write_headers`."""
         lines = []
@@ -765,8 +765,8 @@ class HTTP1ServerConnection(object):
     def __init__(
         self,
         stream: iostream.IOStream,
-        params: HTTP1ConnectionParameters = None,
-        context: object = None,
+        params: Optional[HTTP1ConnectionParameters] = None,
+        context: Optional[object] = None,
     ) -> None:
         """
         :arg stream: an `.IOStream`

tornado/httpclient.py

@@ -87,7 +87,9 @@ class HTTPClient(object):
     """
 
     def __init__(
-        self, async_client_class: Type["AsyncHTTPClient"] = None, **kwargs: Any
+        self,
+        async_client_class: "Optional[Type[AsyncHTTPClient]]" = None,
+        **kwargs: Any
     ) -> None:
         # Initialize self._closed at the beginning of the constructor
         # so that an exception raised here doesn't lead to confusing
@@ -211,7 +213,7 @@ def __new__(cls, force_instance: bool = False, **kwargs: Any) -> "AsyncHTTPClien
             instance_cache[instance.io_loop] = instance
         return instance
 
-    def initialize(self, defaults: Dict[str, Any] = None) -> None:
+    def initialize(self, defaults: Optional[Dict[str, Any]] = None) -> None:
         self.io_loop = IOLoop.current()
         self.defaults = dict(HTTPRequest._DEFAULTS)
         if defaults is not None:
@@ -357,37 +359,39 @@ def __init__(
         self,
         url: str,
         method: str = "GET",
-        headers: Union[Dict[str, str], httputil.HTTPHeaders] = None,
-        body: Union[bytes, str] = None,
-        auth_username: str = None,
-        auth_password: str = None,
-        auth_mode: str = None,
-        connect_timeout: float = None,
-        request_timeout: float = None,
-        if_modified_since: Union[float, datetime.datetime] = None,
-        follow_redirects: bool = None,
-        max_redirects: int = None,
-        user_agent: str = None,
-        use_gzip: bool = None,
-        network_interface: str = None,
-        streaming_callback: Callable[[bytes], None] = None,
-        header_callback: Callable[[str], None] = None,
-        prepare_curl_callback: Callable[[Any], None] = None,
-        proxy_host: str = None,
-        proxy_port: int = None,
-        proxy_username: str = None,
-        proxy_password: str = None,
-        proxy_auth_mode: str = None,
-        allow_nonstandard_methods: bool = None,
-        validate_cert: bool = None,
-        ca_certs: str = None,
-        allow_ipv6: bool = None,
-        client_key: str = None,
-        client_cert: str = None,
-        body_producer: Callable[[Callable[[bytes], None]], "Future[None]"] = None,
+        headers: Optional[Union[Dict[str, str], httputil.HTTPHeaders]] = None,
+        body: Optional[Union[bytes, str]] = None,
+        auth_username: Optional[str] = None,
+        auth_password: Optional[str] = None,
+        auth_mode: Optional[str] = None,
+        connect_timeout: Optional[float] = None,
+        request_timeout: Optional[float] = None,
+        if_modified_since: Optional[Union[float, datetime.datetime]] = None,
+        follow_redirects: Optional[bool] = None,
+        max_redirects: Optional[int] = None,
+        user_agent: Optional[str] = None,
+        use_gzip: Optional[bool] = None,
+        network_interface: Optional[str] = None,
+        streaming_callback: Optional[Callable[[bytes], None]] = None,
+        header_callback: Optional[Callable[[str], None]] = None,
+        prepare_curl_callback: Optional[Callable[[Any], None]] = None,
+        proxy_host: Optional[str] = None,
+        proxy_port: Optional[int] = None,
+        proxy_username: Optional[str] = None,
+        proxy_password: Optional[str] = None,
+        proxy_auth_mode: Optional[str] = None,
+        allow_nonstandard_methods: Optional[bool] = None,
+        validate_cert: Optional[bool] = None,
+        ca_certs: Optional[str] = None,
+        allow_ipv6: Optional[bool] = None,
+        client_key: Optional[str] = None,
+        client_cert: Optional[str] = None,
+        body_producer: Optional[
+            Callable[[Callable[[bytes], None]], "Future[None]"]
+        ] = None,
         expect_100_continue: bool = False,
-        decompress_response: bool = None,
-        ssl_options: Union[Dict[str, Any], ssl.SSLContext] = None,
+        decompress_response: Optional[bool] = None,
+        ssl_options: Optional[Union[Dict[str, Any], ssl.SSLContext]] = None,
     ) -> None:
         r"""All parameters except ``url`` are optional.
 
@@ -624,14 +628,14 @@ def __init__(
         self,
         request: HTTPRequest,
         code: int,
-        headers: httputil.HTTPHeaders = None,
-        buffer: BytesIO = None,
-        effective_url: str = None,
-        error: BaseException = None,
-        request_time: float = None,
-        time_info: Dict[str, float] = None,
-        reason: str = None,
-        start_time: float = None,
+        headers: Optional[httputil.HTTPHeaders] = None,
+        buffer: Optional[BytesIO] = None,
+        effective_url: Optional[str] = None,
+        error: Optional[BaseException] = None,
+        request_time: Optional[float] = None,
+        time_info: Optional[Dict[str, float]] = None,
+        reason: Optional[str] = None,
+        start_time: Optional[float] = None,
     ) -> None:
         if isinstance(request, _RequestProxy):
             self.request = request.request
@@ -703,7 +707,10 @@ class HTTPClientError(Exception):
     """
 
     def __init__(
-        self, code: int, message: str = None, response: HTTPResponse = None
+        self,
+        code: int,
+        message: Optional[str] = None,
+        response: Optional[HTTPResponse] = None,
     ) -> None:
         self.code = code
         self.message = message or httputil.responses.get(code, "Unknown")