Complete type annotations in pip/_internal/cli (#10169)

Author: harupy

src/pip/_internal/cli/autocompletion.py

@@ -29,7 +29,7 @@ def autocomplete() -> None:
     options = []
 
     # subcommand
-    subcommand_name = None  # type: Optional[str]
+    subcommand_name: Optional[str] = None
     for word in cwords:
         if word in subcommands:
             subcommand_name = word

src/pip/_internal/cli/base_command.py

@@ -40,8 +40,8 @@
 
 
 class Command(CommandContextMixIn):
-    usage = None  # type: str
-    ignore_require_venv = False  # type: bool
+    usage: str = ""
+    ignore_require_venv: bool = False
 
     def __init__(self, name: str, summary: str, isolated: bool = False) -> None:
         super().__init__()
@@ -58,7 +58,7 @@ def __init__(self, name: str, summary: str, isolated: bool = False) -> None:
             isolated=isolated,
         )
 
-        self.tempdir_registry = None  # type: Optional[TempDirRegistry]
+        self.tempdir_registry: Optional[TempDirRegistry] = None
 
         # Commands should add options to this option group
         optgroup_name = f"{self.name.capitalize()} Options"