add only required imports to spinners and progress bar

Author: sinscary

src/pip/_internal/cli/progress_bars.py

@@ -1,7 +1,4 @@
-# The following comment should be removed at some point in the future.
-# mypy: strict-optional=False
-
-from __future__ import absolute_import, division
+from __future__ import division
 
 import contextlib
 import itertools
@@ -11,7 +8,6 @@
 from signal import SIGINT, default_int_handler, signal
 
 from pip._vendor import six
-from pip._vendor.progress import HIDE_CURSOR, SHOW_CURSOR
 from pip._vendor.progress.bar import Bar, FillingCirclesBar, IncrementalBar
 from pip._vendor.progress.spinner import Spinner
 
@@ -30,9 +26,6 @@
 except Exception:
     colorama = None
 
-logger = logging.getLogger(__name__)
-
-
 def _select_progress_class(preferred, fallback):
     encoding = getattr(preferred.file, "encoding", None)
 

src/pip/_internal/cli/spinners.py

@@ -1,3 +1,21 @@
+from __future__ import absolute_import, division
+
+import contextlib
+import itertools
+import logging
+import sys
+import time
+
+from pip._vendor.progress import HIDE_CURSOR, SHOW_CURSOR
+
+from pip._internal.utils.compat import WINDOWS
+from pip._internal.utils.logging import get_indentation
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+if MYPY_CHECK_RUNNING:
+    from typing import Iterator, IO
+
+logger = logging.getLogger(__name__)
+
 class SpinnerInterface(object):
     def spin(self):
         # type: () -> None