pprint stream type (#178)

* Use less strict IO[str] instead of TextIO

* IO[Any] should be IO[str]

See also discussion in #17.

stdlib/2.7/pprint.pyi

@@ -4,7 +4,7 @@
 
 from typing import IO, Any
 
-def pprint(object: Any, stream: IO[Any] = ..., indent: int = ..., width: int = ...,
+def pprint(object: Any, stream: IO[str] = ..., indent: int = ..., width: int = ...,
            depth: int = ...) -> None: ...
 def pformat(object, indent=..., width=..., depth=...): ...
 def saferepr(object): ...
@@ -13,7 +13,7 @@ def isrecursive(object): ...
 
 class PrettyPrinter:
     def __init__(self, indent: int = ..., width: int = ..., depth: int = ...,
-                 stream: IO[Any] = ...) -> None: ...
+                 stream: IO[str] = ...) -> None: ...
     def pprint(self, object): ...
     def pformat(self, object): ...
     def isrecursive(self, object): ...

stdlib/3/pprint.pyi

@@ -2,11 +2,11 @@
 
 # Based on http://docs.python.org/3.2/library/pprint.html
 
-from typing import Any, Dict, Tuple, TextIO
+from typing import Any, Dict, Tuple, IO
 
 def pformat(o: object, indent: int = ..., width: int = ...,
             depth: int = ...) -> str: ...
-def pprint(o: object, stream: TextIO = ..., indent: int = ..., width: int = ...,
+def pprint(o: object, stream: IO[str] = ..., indent: int = ..., width: int = ...,
            depth: int = ...) -> None: ...
 def isreadable(o: object) -> bool: ...
 def isrecursive(o: object) -> bool: ...
@@ -14,7 +14,7 @@ def saferepr(o: object) -> str: ...
 
 class PrettyPrinter:
     def __init__(self, indent: int = ..., width: int = ..., depth: int = ...,
-                 stream: TextIO = ...) -> None: ...
+                 stream: IO[str] = ...) -> None: ...
     def pformat(self, o: object) -> str: ...
     def pprint(self, o: object) -> None: ...
     def isreadable(self, o: object) -> bool: ...