TST/CLN: Avoid subprocess shell=True (#49033)

Author: mroeschke

pandas/_config/localization.py

@@ -7,12 +7,10 @@
 
 from contextlib import contextmanager
 import locale
+import platform
 import re
 import subprocess
-from typing import (
-    Callable,
-    Generator,
-)
+from typing import Generator
 
 from pandas._config.config import options
 
@@ -107,15 +105,10 @@ def _valid_locales(locales: list[str] | str, normalize: bool) -> list[str]:
     ]
 
 
-def _default_locale_getter() -> bytes:
-    return subprocess.check_output(["locale -a"], shell=True)
-
-
 def get_locales(
     prefix: str | None = None,
     normalize: bool = True,
-    locale_getter: Callable[[], bytes] = _default_locale_getter,
-) -> list[str] | None:
+) -> list[str]:
     """
     Get all the locales that are available on the system.
 
@@ -129,9 +122,6 @@ def get_locales(
         Call ``locale.normalize`` on the resulting list of available locales.
         If ``True``, only locales that can be set without throwing an
         ``Exception`` are returned.
-    locale_getter : callable
-        The function to use to retrieve the current locales. This should return
-        a string with each locale separated by a newline character.
 
     Returns
     -------
@@ -141,15 +131,15 @@ def get_locales(
 
             locale.setlocale(locale.LC_ALL, locale_string)
 
-    On error will return None (no locale available, e.g. Windows)
+    On error will return an empty list (no locale available, e.g. Windows)
 
     """
-    try:
-        raw_locales = locale_getter()
-    except subprocess.CalledProcessError:
-        # Raised on (some? all?) Windows platforms because Note: "locale -a"
-        #  is not defined
-        return None
+    if platform.system() in ("Linux", "Darwin"):
+        raw_locales = subprocess.check_output(["locale", "-a"])
+    else:
+        # Other platforms e.g. windows platforms don't define "locale -a"
+        #  Note: is_platform_windows causes circular import here
+        return []
 
     try:
         # raw_locales is "\n" separated list of locales

pandas/tests/config/test_localization.py

@@ -12,7 +12,7 @@
 
 import pandas as pd
 
-_all_locales = get_locales() or []
+_all_locales = get_locales()
 _current_locale = locale.setlocale(locale.LC_ALL)  # getlocale() is wrong, see GH#46595
 
 # Don't run any of these tests if we have no locales.

pandas/tests/indexes/datetimes/test_misc.py

@@ -193,7 +193,7 @@ def test_datetimeindex_accessors6(self):
     # GH 12806
     # error: Unsupported operand types for + ("List[None]" and "List[str]")
     @pytest.mark.parametrize(
-        "time_locale", [None] + (tm.get_locales() or [])  # type: ignore[operator]
+        "time_locale", [None] + tm.get_locales()  # type: ignore[operator]
     )
     def test_datetime_name_accessors(self, time_locale):
         # Test Monday -> Sunday and January -> December, in that sequence

pandas/tests/scalar/timestamp/test_timestamp.py

@@ -153,7 +153,7 @@ def test_is_end(self, end, tz):
     )
     # error: Unsupported operand types for + ("List[None]" and "List[str]")
     @pytest.mark.parametrize(
-        "time_locale", [None] + (tm.get_locales() or [])  # type: ignore[operator]
+        "time_locale", [None] + tm.get_locales()  # type: ignore[operator]
     )
     def test_names(self, data, time_locale):
         # GH 17354

pandas/tests/series/accessors/test_dt_accessor.py

@@ -432,7 +432,7 @@ def test_dt_accessor_no_new_attributes(self):
 
     # error: Unsupported operand types for + ("List[None]" and "List[str]")
     @pytest.mark.parametrize(
-        "time_locale", [None] + (tm.get_locales() or [])  # type: ignore[operator]
+        "time_locale", [None] + tm.get_locales()  # type: ignore[operator]
     )
     def test_dt_accessor_datetime_name_accessors(self, time_locale):
         # Test Monday -> Sunday and January -> December, in that sequence