Some test cleanups suggested by Barry

ncoghlan · ncoghlan · commit d12b4126779b · 2017-03-15T17:32:12.000+10:00
diff --git a/Lib/test/test_locale_coercion.py b/Lib/test/test_locale_coercion.py
@@ -85,7 +85,7 @@ def test_C_utf8_locale(self):
             "LC_CTYPE": "",
             "LC_ALL": "",
         }
-        for env_var in ("LC_ALL", "LC_CTYPE", "LANG"):
+        for env_var in base_var_dict:
             with self.subTest(env_var=env_var):
                 var_dict = base_var_dict.copy()
                 var_dict[env_var] = "C.UTF-8"
@@ -112,7 +112,7 @@ def _check_c_locale_coercion(self, expected_fsencoding, coerce_c_locale):
             "LC_CTYPE": "",
             "LC_ALL": "",
         }
-        for env_var in ("LC_ALL", "LC_CTYPE", "LANG"):
+        for env_var in base_var_dict:
             for locale_to_set in ("", "C", "POSIX", "invalid.ascii"):
                 with self.subTest(env_var=env_var,
                                   nominal_locale=locale_to_set,
@@ -161,12 +161,9 @@ def setUp(self):
         # This is needed otherwise we get a fatal error:
         # "Py_Initialize: Unable to get the locale encoding
         # LookupError: no codec search functions registered: can't find encoding"
-        self.oldcwd = os.getcwd()
+        self.addCleanup(os.chdir, os.getcwd())
         os.chdir(basepath)
 
-    def tearDown(self):
-        os.chdir(self.oldcwd)
-
     def run_embedded_interpreter(self, *args):
         """Runs a test in the embedded interpreter"""
         cmd = [self.test_exe]
