Use explicit "# type: str" instead of '' shortcut.

builtins/2.7/__builtin__.pyi

@@ -24,7 +24,7 @@ classmethod = object()  # Special, only valid as a decorator.
 property = object()
 
 class object:
-    __doc__ = ''
+    __doc__ = ...  # type: str
     __class__ = ...  # type: type
 
     def __init__(self) -> None: ...
@@ -35,8 +35,8 @@ class object:
     def __hash__(self) -> int: ...
 
 class type:
-    __name__ = ''
-    __module__ = ''
+    __name__ = ...  # type: str
+    __module__ = ...  # type: str
     __dict__ = ...  # type: Dict[unicode, Any]
 
     @overload
@@ -461,8 +461,8 @@ class tuple(Sequence[_T_co], Generic[_T_co]):
 
 class function:
     # TODO name of the class (corresponds to Python 'function' class)
-    __name__ = ''
-    __module__ = ''
+    __name__ = ...  # type: str
+    __module__ = ...  # type: str
 
 class list(MutableSequence[_T], Reversible[_T], Generic[_T]):
     @overload
@@ -594,8 +594,8 @@ class xrange(Sized, Iterable[int], Reversible[int]):
     def __reversed__(self) -> Iterator[int]: ...
 
 class module:
-    __name__ = ''
-    __file__ = ''
+    __name__ = ...  # type: str
+    __file__ = ...  # type: str
     __dict__ = ...  # type: Dict[unicode, Any]
 
 True = ...  # type: bool
@@ -757,8 +757,9 @@ class ArithmeticError(StandardError): ...
 class BufferError(StandardError): ...
 class EnvironmentError(StandardError):
     errno = 0
-    strerror = ''
-    filename = '' # TODO can this be unicode?
+    strerror = ...  # type: str
+    # TODO can this be unicode?
+    filename = ...  # type: str
 class LookupError(StandardError): ...
 class RuntimeError(StandardError): ...
 class ValueError(StandardError): ...

builtins/2.7/sys.pyi

@@ -40,7 +40,7 @@ class _version_info(Tuple[int, int, int, str, int]):
     major = 0
     minor = 0
     micro = 0
-    releaselevel = ''
+    releaselevel = ...  # type: str
     serial = 0
 
 _mercurial = ...  # type: Tuple[str, str, str]
@@ -75,8 +75,8 @@ version = ...  # type: str
 warnoptions = ...  # type: object
 float_info = ...  # type: _float_info
 version_info = ...  # type: _version_info
-ps1 = ''
-ps2 = ''
+ps1 = ...  # type: str
+ps2 = ...  # type: str
 last_type = ...  # type: type
 last_value = ...  # type: BaseException
 last_traceback = ...  # type: TracebackType