Add mypy annotations to init and check in commands

Author: deveshks

src/pip/_internal/commands/__init__.py

@@ -2,9 +2,6 @@
 Package containing all pip commands
 """
 
-# The following comment should be removed at some point in the future.
-# mypy: disallow-untyped-defs=False
-
 from __future__ import absolute_import
 
 import importlib
@@ -13,7 +10,7 @@
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any
+    from typing import Any, Union, Sequence
     from pip._internal.cli.base_command import Command
 
 
@@ -101,6 +98,7 @@ def create_command(name, **kwargs):
 
 
 def get_similar_commands(name):
+    # type: (str) -> Union[bool, Sequence[str]]
     """Command name auto-correct."""
     from difflib import get_close_matches
 

src/pip/_internal/commands/check.py

@@ -1,6 +1,3 @@
-# The following comment should be removed at some point in the future.
-# mypy: disallow-untyped-defs=False
-
 import logging
 
 from pip._internal.cli.base_command import Command
@@ -9,9 +6,14 @@
     create_package_set_from_installed,
 )
 from pip._internal.utils.misc import write_output
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 logger = logging.getLogger(__name__)
 
+if MYPY_CHECK_RUNNING:
+    from typing import List, Any
+    from optparse import Values
+
 
 class CheckCommand(Command):
     """Verify installed packages have compatible dependencies."""
@@ -20,6 +22,7 @@ class CheckCommand(Command):
       %prog [options]"""
 
     def run(self, options, args):
+        # type: (Values, List[Any]) -> Any
         package_set, parsing_probs = create_package_set_from_installed()
         missing, conflicting = check_package_set(package_set)