Fixes to tempfile stubs (#981)

Fixes #975

And a few more things I noticed while reading the tempfile docs.

    In 3.5, most functions in tempfile were changed to accept either str or bytes in their prefix and suffix arguments, and return bytes or str accordingly. This seemed like a case for AnyStr.
    We were missing tempdirb and tempprefixb, added in 3.5.
    TemporaryFile and others were declared as returning BinaryIO, but they actually return either binary or text IO depending on the mode passed in. I changed the return type to IO[Any], similar to builtins.open.

stdlib/2/tempfile.pyi

@@ -86,16 +86,16 @@ class TemporaryDirectory:
 @overload
 def mkstemp() -> Tuple[int, str]: ...
 @overload
-def mkstemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: AnyStr = ...,
+def mkstemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: Optional[AnyStr] = ...,
             text: bool = ...) -> Tuple[int, AnyStr]: ...
 @overload
 def mkdtemp() -> str: ...
 @overload
-def mkdtemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: AnyStr = ...) -> AnyStr: ...
+def mkdtemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: Optional[AnyStr] = ...) -> AnyStr: ...
 @overload
 def mktemp() -> str: ...
 @overload
-def mktemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: AnyStr = ...) -> AnyStr: ...
+def mktemp(suffix: AnyStr = ..., prefix: AnyStr = ..., dir: Optional[AnyStr] = ...) -> AnyStr: ...
 def gettempdir() -> str: ...
 def gettempprefix() -> str: ...
 

stdlib/3/tempfile.pyi

@@ -3,49 +3,88 @@
 
 # based on http://docs.python.org/3.3/library/tempfile.html
 
+import sys
 from types import TracebackType
-from typing import BinaryIO, Optional, Tuple, Type
+from typing import Any, AnyStr, Generic, IO, Optional, Tuple, Type
 
 # global variables
-tempdir = ...  # type: str
+tempdir = ...  # type: Optional[str]
 template = ...  # type: str
 
-# TODO text files
 
-# function stubs
-def TemporaryFile(
-    mode: str = ..., buffering: int = ..., encoding: str = ...,
-    newline: str = ..., suffix: str = ..., prefix: str = ...,
-    dir: str = ...
-) -> BinaryIO:
-    ...
-def NamedTemporaryFile(
-    mode: str = ..., buffering: int = ..., encoding: str = ...,
-    newline: str = ..., suffix: str = ..., prefix: str = ...,
-    dir: str = ..., delete: bool =...
-) -> BinaryIO:
-    ...
-def SpooledTemporaryFile(
-    max_size: int = ..., mode: str = ..., buffering: int = ...,
-    encoding: str = ..., newline: str = ..., suffix: str = ...,
-    prefix: str = ..., dir: str = ...
-) -> BinaryIO:
-    ...
+if sys.version_info >= (3, 5):
+    def TemporaryFile(
+        mode: str = ..., buffering: int = ..., encoding: str = ...,
+        newline: str = ..., suffix: Optional[AnyStr]= ..., prefix: Optional[AnyStr] = ...,
+        dir: Optional[AnyStr] = ...
+    ) -> IO[Any]:
+        ...
+    def NamedTemporaryFile(
+        mode: str = ..., buffering: int = ..., encoding: str = ...,
+        newline: str = ..., suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ...,
+        dir: Optional[AnyStr] = ..., delete: bool =...
+    ) -> IO[Any]:
+        ...
+    def SpooledTemporaryFile(
+        max_size: int = ..., mode: str = ..., buffering: int = ...,
+        encoding: str = ..., newline: str = ..., suffix: Optional[AnyStr] = ...,
+        prefix: Optional[AnyStr] = ..., dir: Optional[AnyStr] = ...
+    ) -> IO[Any]:
+        ...
 
-class TemporaryDirectory:
-    name = ...  # type: str
-    def __init__(self, suffix: str = ..., prefix: str = ...,
-                 dir: str = ...) -> None: ...
-    def cleanup(self) -> None: ...
-    def __enter__(self) -> str: ...
-    def __exit__(self, exc_type: Optional[Type[BaseException]],
-                 exc_val: Optional[Exception],
-                 exc_tb: Optional[TracebackType]) -> bool: ...
+    class TemporaryDirectory(Generic[AnyStr]):
+        name = ...  # type: str
+        def __init__(self, suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ...,
+                     dir: Optional[AnyStr] = ...) -> None: ...
+        def cleanup(self) -> None: ...
+        def __enter__(self) -> AnyStr: ...
+        def __exit__(self, exc_type: Optional[Type[BaseException]],
+                     exc_val: Optional[BaseException],
+                     exc_tb: Optional[TracebackType]) -> bool: ...
+
+    def mkstemp(suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ..., dir: Optional[AnyStr] = ...,
+                text: bool = ...) -> Tuple[int, AnyStr]: ...
+    def mkdtemp(suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ...,
+                dir: Optional[str] = ...) -> AnyStr: ...
+    def mktemp(suffix: Optional[AnyStr] = ..., prefix: Optional[AnyStr] = ..., dir: Optional[AnyStr] = ...) -> AnyStr: ...
+
+    def gettempdirb() -> bytes: ...
+    def gettempprefixb() -> bytes: ...
+else:
+    def TemporaryFile(
+        mode: str = ..., buffering: int = ..., encoding: str = ...,
+        newline: str = ..., suffix: str = ..., prefix: str = ...,
+        dir: Optional[str] = ...
+    ) -> IO[Any]:
+        ...
+    def NamedTemporaryFile(
+        mode: str = ..., buffering: int = ..., encoding: str = ...,
+        newline: str = ..., suffix: str = ..., prefix: str = ...,
+        dir: Optional[str] = ..., delete: bool =...
+    ) -> IO[Any]:
+        ...
+    def SpooledTemporaryFile(
+        max_size: int = ..., mode: str = ..., buffering: int = ...,
+        encoding: str = ..., newline: str = ..., suffix: str = ...,
+        prefix: str = ..., dir: Optional[str] = ...
+    ) -> IO[Any]:
+        ...
+
+    class TemporaryDirectory:
+        name = ...  # type: str
+        def __init__(self, suffix: str = ..., prefix: str = ...,
+                     dir: Optional[str] = ...) -> None: ...
+        def cleanup(self) -> None: ...
+        def __enter__(self) -> str: ...
+        def __exit__(self, exc_type: Optional[Type[BaseException]],
+                     exc_val: Optional[BaseException],
+                     exc_tb: Optional[TracebackType]) -> bool: ...
+
+    def mkstemp(suffix: str = ..., prefix: str = ..., dir: Optional[str] = ...,
+                text: bool = ...) -> Tuple[int, str]: ...
+    def mkdtemp(suffix: str = ..., prefix: str = ...,
+                dir: Optional[str] = ...) -> str: ...
+    def mktemp(suffix: str = ..., prefix: str = ..., dir: Optional[str] = ...) -> str: ...
 
-def mkstemp(suffix: str = ..., prefix: str = ..., dir: str = ...,
-            text: bool = ...) -> Tuple[int, str]: ...
-def mkdtemp(suffix: str = ..., prefix: str = ...,
-            dir: str = ...) -> str: ...
-def mktemp(suffix: str = ..., prefix: str = ..., dir: str = ...) -> str: ...
 def gettempdir() -> str: ...
 def gettempprefix() -> str: ...