Merge pull request #5925 from mbaluna/mypy-annotations-for-utils-appdirs

Add mypy annotations for utils/appdirs

Author: pradyunsg

src/pip/_internal/utils/appdirs.py

@@ -10,9 +10,16 @@
 from pip._vendor.six import PY2, text_type
 
 from pip._internal.utils.compat import WINDOWS, expanduser
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (  # noqa: F401
+        List, Union
+    )
 
 
 def user_cache_dir(appname):
+    # type: (str) -> str
     r"""
     Return full path to the user-specific cache dir for this application.
 
@@ -61,6 +68,7 @@ def user_cache_dir(appname):
 
 
 def user_data_dir(appname, roaming=False):
+    # type: (str, bool) -> str
     r"""
     Return full path to the user-specific data dir for this application.
 
@@ -113,6 +121,7 @@ def user_data_dir(appname, roaming=False):
 
 
 def user_config_dir(appname, roaming=True):
+    # type: (str, bool) -> str
     """Return full path to the user-specific config dir for this application.
 
         "appname" is the name of application.
@@ -146,6 +155,7 @@ def user_config_dir(appname, roaming=True):
 # for the discussion regarding site_config_dirs locations
 # see <https://github.com/pypa/pip/issues/1733>
 def site_config_dirs(appname):
+    # type: (str) -> List[str]
     r"""Return a list of potential user-shared config dirs for this application.
 
         "appname" is the name of application.
@@ -186,6 +196,7 @@ def site_config_dirs(appname):
 # -- Windows support functions --
 
 def _get_win_folder_from_registry(csidl_name):
+    # type: (str) -> str
     """
     This is a fallback technique at best. I'm not sure if using the
     registry for this guarantees us the correct answer for all CSIDL_*
@@ -208,6 +219,7 @@ def _get_win_folder_from_registry(csidl_name):
 
 
 def _get_win_folder_with_ctypes(csidl_name):
+    # type: (str) -> str
     csidl_const = {
         "CSIDL_APPDATA": 26,
         "CSIDL_COMMON_APPDATA": 35,