Rename .py to .pyi.

2.7/_collections.pyi

@@ -0,0 +1,41 @@
+"""Stub file for the '_collections' module."""
+# This is an autogenerated file. It serves as a starting point
+# for a more precise manual annotation of this module.
+# Feel free to edit the source below, but remove this header when you do.
+
+from typing import List, Tuple, Dict, Undefined, GenericType
+
+class defaultdict(object):
+    def __copy__() -> object: ...
+    def __missing__(*args, **kwargs) -> object:
+        raise KeyError()
+    def __reduce__() -> tuple: ...
+    def copy() -> object: ...
+
+class deque(object):
+    def __copy__() -> object: ...
+    def __reduce__() -> tuple: ...
+    def __reversed__() -> object: ...
+    def __sizeof__() -> long: ...
+    def append(*args, **kwargs) -> None: ...
+    def appendleft(*args, **kwargs) -> None: ...
+    def clear() -> None: ...
+    def count(*args, **kwargs) -> int:
+        raise RuntimeError()
+    def extend(*args, **kwargs) -> None: ...
+    def extendleft(*args, **kwargs) -> None: ...
+    def pop() -> object:
+        raise IndexError()
+    def popleft() -> object:
+        raise IndexError()
+    def remove(*args, **kwargs) -> None:
+        raise IndexError()
+        raise ValueError()
+    def reverse() -> None: ...
+    def rotate(*args, **kwargs) -> None: ...
+
+class deque_iterator(object):
+    def __length_hint__() -> int: ...
+
+class deque_reverse_iterator(object):
+    def __length_hint__() -> int: ...