Use Literal in a few more places (#3176)

stdlib/2and3/xml/etree/ElementTree.pyi

@@ -1,10 +1,14 @@
 # Stubs for xml.etree.ElementTree
 
 from typing import Any, Callable, Dict, Generator, IO, ItemsView, Iterable, Iterator, KeysView, List, MutableSequence, Optional, overload, Sequence, Text, Tuple, TypeVar, Union
-from typing_extensions import Literal
 import io
 import sys
 
+if sys.version_info < (3,) or sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 VERSION: str
 
 class ParseError(SyntaxError):

stdlib/3/_winapi.pyi

@@ -1,5 +1,11 @@
+import sys
 from typing import Any, Union, Tuple, Optional, overload, Dict, NoReturn, Sequence
 
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 CREATE_NEW_CONSOLE: int
 CREATE_NEW_PROCESS_GROUP: int
 DUPLICATE_CLOSE_SOURCE: int
@@ -46,11 +52,12 @@ WAIT_TIMEOUT: int
 
 def CloseHandle(handle: int) -> None: ...
 
-# TODO: once literal types are supported, overload with Literal[True/False]
 @overload
-def ConnectNamedPipe(handle: int, overlapped: Union[int, bool]) -> Any: ...
+def ConnectNamedPipe(handle: int, overlapped: Literal[True]) -> Overlapped: ...
 @overload
-def ConnectNamedPipe(handle: int) -> None: ...
+def ConnectNamedPipe(handle: int, overlapped: Literal[False] = ...) -> None: ...
+@overload
+def ConnectNamedPipe(handle: int, overlapped: bool) -> Any: ...
 
 def CreateFile(file_name: str, desired_access: int, share_mode: int, security_attributes: int, creation_disposition: int, flags_and_attributes: int, template_file: int) -> int: ...
 def CreateJunction(src_path: str, dest_path: str) -> None: ...

stdlib/3/ast.pyi

@@ -1,12 +1,9 @@
-# Python 3.5 ast
-
 import sys
 # Rename typing to _typing, as not to conflict with typing imported
 # from _ast below when loaded in an unorthodox way by the Dropbox
 # internal Bazel integration.
 import typing as _typing
 from typing import overload, Any, Iterator, Optional, Union, TypeVar
-from typing_extensions import Literal
 
 # The same unorthodox Bazel integration causes issues with sys, which
 # is imported in both modules. unfortunately we can't just rename sys,
@@ -14,6 +11,11 @@ from typing_extensions import Literal
 # sys.
 from _ast import *  # type: ignore
 
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 class NodeVisitor():
     def visit(self, node: AST) -> Any: ...
     def generic_visit(self, node: AST) -> Any: ...

stdlib/3/gettext.pyi

@@ -1,7 +1,10 @@
-# Stubs for gettext (Python 3.4)
-
+import sys
 from typing import overload, Any, Container, IO, Iterable, Optional, Type, TypeVar
-from typing_extensions import Literal
+
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
 
 class NullTranslations:
     def __init__(self, fp: IO[str] = ...) -> None: ...

stdlib/3/subprocess.pyi

@@ -7,9 +7,13 @@ from typing import (
     Generic, TypeVar, AnyStr,
     overload,
 )
-from typing_extensions import Literal
 from types import TracebackType
 
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 # We prefer to annotate inputs to methods (eg subprocess.check_call) with these
 # union types.
 # For outputs we use laborious literal based overloads to try to determine

third_party/2and3/werkzeug/wrappers.pyi

@@ -1,8 +1,8 @@
+import sys
 from datetime import datetime
 from typing import (
-    Any, Callable, Iterable, Iterator, Mapping, MutableMapping, Optional, Sequence, Text, Tuple, Type, TypeVar, Union,
+    Any, Callable, Iterable, Iterator, Mapping, MutableMapping, Optional, Sequence, Text, Tuple, Type, TypeVar, Union, overload
 )
-
 from wsgiref.types import WSGIEnvironment, InputStream
 
 from .datastructures import (
@@ -12,6 +12,11 @@ from .datastructures import (
 )
 from .useragents import UserAgent
 
+if sys.version_info >= (3, 8):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 class BaseRequest:
     charset: str
     encoding_errors: str
@@ -44,8 +49,16 @@ class BaseRequest:
     args: ImmutableMultiDict
     @property
     def data(self) -> bytes: ...
-    # TODO: once Literal types are supported, overload with as_text
-    def get_data(self, cache: bool = ..., as_text: bool = ..., parse_form_data: bool = ...) -> Any: ...  # returns bytes if as_text is False (the default), else Text
+    @overload
+    def get_data(self, cache: bool = ..., as_text: Literal[False] = ..., parse_form_data: bool = ...) -> bytes: ...
+    @overload
+    def get_data(self, cache: bool, as_text: Literal[True], parse_form_data: bool = ...) -> Text: ...
+    @overload
+    def get_data(self, *, as_text: Literal[True], parse_form_data: bool = ...) -> Text: ...
+    @overload
+    def get_data(self, cache: bool, as_text: bool, parse_form_data: bool = ...) -> Any: ...
+    @overload
+    def get_data(self, *, as_text: bool, parse_form_data: bool = ...) -> Any: ...
     form: ImmutableMultiDict
     values: CombinedMultiDict
     files: MultiDict
@@ -107,8 +120,12 @@ class BaseResponse:
     def force_type(cls: Type[_SelfT], response: object, environ: Optional[WSGIEnvironment] = ...) -> _SelfT: ...
     @classmethod
     def from_app(cls: Type[_SelfT], app: Any, environ: WSGIEnvironment, buffered: bool = ...) -> _SelfT: ...
-    # TODO: once Literal types are supported, overload with as_text
-    def get_data(self, as_text: bool = ...) -> Any: ...  # returns bytes if as_text is False (the default), else Text
+    @overload
+    def get_data(self, as_text: Literal[False] = ...) -> bytes: ...
+    @overload
+    def get_data(self, as_text: Literal[True]) -> Text: ...
+    @overload
+    def get_data(self, as_text: bool) -> Any: ...
     def set_data(self, value: Union[bytes, Text]) -> None: ...
     data: Any
     def calculate_content_length(self) -> Optional[int]: ...