Satisfy mypy for library as-is

Without adding any annotations, make sure mypy is happy.

4 files changed, 18 insertions, 6 deletions

diff --git a/natsort/compat/fake_fastnumbers.py b/natsort/compat/fake_fastnumbers.py
index 7177551..570083f 100644
--- a/natsort/compat/fake_fastnumbers.py
+++ b/natsort/compat/fake_fastnumbers.py
@@ -10,7 +10,7 @@ import unicodedata
 # Local imports.
 from natsort.unicode_numbers import decimal_chars
 
-NAN_INF = [
+_NAN_INF = [
     "INF",
     "INf",
     "Inf",
@@ -28,8 +28,8 @@ NAN_INF = [
     "nAN",
     "Nan",
 ]
-NAN_INF.extend(["+" + x[:2] for x in NAN_INF] + ["-" + x[:2] for x in NAN_INF])
-NAN_INF = frozenset(NAN_INF)
+_NAN_INF.extend(["+" + x[:2] for x in _NAN_INF] + ["-" + x[:2] for x in _NAN_INF])
+NAN_INF = frozenset(_NAN_INF)
 ASCII_NUMS = "0123456789+-"
 POTENTIAL_FIRST_CHAR = frozenset(decimal_chars + list(ASCII_NUMS + "."))
 
diff --git a/natsort/compat/locale.py b/natsort/compat/locale.py
index ccb5592..1edb67f 100644
--- a/natsort/compat/locale.py
+++ b/natsort/compat/locale.py
@@ -3,9 +3,8 @@
 Interface for natsort to access locale functionality without
 having to worry about if it is using PyICU or the built-in locale.
 """
-
-# Std. lib imports.
 import sys
+import typing as t
 
 # This string should be sorted after any other byte string because
 # it contains the max unicode character repeated 20 times.
@@ -13,6 +12,11 @@ import sys
 null_string = ""
 null_string_max = chr(sys.maxunicode) * 20
 
+# This variable could be str or bytes depending on the locale library
+# being used, so give the type-checker this information.
+null_string_locale: t.Union[str, bytes]
+null_string_locale_max: t.Union[str, bytes]
+
 # strxfrm can be buggy (especially on BSD-based systems),
 # so prefer icu if available.
 try:  # noqa: C901
diff --git a/natsort/natsort.py b/natsort/natsort.py
index 0430a44..1402cf8 100644
--- a/natsort/natsort.py
+++ b/natsort/natsort.py
@@ -622,7 +622,7 @@ def _split_apply(v, key=None):
 # Choose the implementation based on the host OS
 if platform.system() == "Windows":
 
-    from ctypes import wintypes, windll
+    from ctypes import wintypes, windll  # type: ignore
     from functools import cmp_to_key
 
     _windows_sort_cmp = windll.Shlwapi.StrCmpLogicalW
diff --git a/setup.cfg b/setup.cfg
index a045246..93c0f1c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -63,3 +63,11 @@ exclude =
 	dist,
 	docs,
 	.venv
+
+[mypy]
+
+[mypy-icu]
+ignore_missing_imports = True
+
+[mypy-fastnumbers]
+ignore_missing_imports = True