Consider __doc__ always Optional. (#641)

python/mypy#2380 showed a discrepancy between object and FunctionType in stdlib2. The first defined __doc__ to be str, the second Optional[str]. As FunctionType depends on object, this is no longer valid.

As suggested by @gvanrossum in python/mypy#2380, all __doc__ should be considered Optional.

(Final verdict was just to remove most __doc__ attributes since it's inherited from object.)

third_party/2/sqlalchemy/util/langhelpers.pyi

@@ -48,7 +48,6 @@ def as_interface(obj, cls=..., methods=..., required=...): ...
 
 class memoized_property:
     fget = ... # type: Any
-    __doc__ = ... # type: Any
     __name__ = ... # type: Any
     def __init__(self, fget, doc=...) -> None: ...
     def __get__(self, obj, cls): ...
@@ -92,7 +91,6 @@ def assert_arg_type(arg, argtype, name): ...
 def dictlike_iteritems(dictlike): ...
 
 class classproperty:
-    __doc__ = ... # type: Any
     def __init__(self, fget, *arg, **kw) -> None: ...
     def __get__(desc, self, cls): ...
 

third_party/3/typed_ast/ast27.pyi

@@ -2,12 +2,10 @@ import typing
 from typing import Any, Optional, Union, Generic, Iterator
 
 class NodeVisitor():
-    __doc__ = ...  # type: str
     def visit(self, node: AST) -> Any: ...
     def generic_visit(self, node: AST) -> None: ...
 
 class NodeTransformer(NodeVisitor):
-    __doc__ = ...  # type: str
     def generic_visit(self, node: AST) -> None: ...
 
 def parse(source: Union[str, bytes], filename: Union[str, bytes] = ..., mode: str = ...) -> AST: ...

third_party/3/typed_ast/ast35.pyi

@@ -2,12 +2,10 @@ import typing
 from typing import Any, Optional, Union, Generic, Iterator
 
 class NodeVisitor():
-    __doc__ = ...  # type: str
     def visit(self, node: AST) -> Any: ...
     def generic_visit(self, node: AST) -> None: ...
 
 class NodeTransformer(NodeVisitor):
-    __doc__ = ...  # type: str
     def generic_visit(self, node: AST) -> None: ...
 
 def parse(source: Union[str, bytes], filename: Union[str, bytes] = ..., mode: str = ...) -> AST: ...