Fix test_embed.test_pre_initialization_sys_options() env vars (GH-14172)

test_pre_initialization_sys_options() of test_embed now removes PYTHON* environment variables like PYTHONWARNINGS. (cherry picked from commit dbdc991) Co-authored-by: Victor Stinner <vstinner@redhat.com>

Author: miss-islington

Lib/test/test_embed.py

@@ -26,6 +26,15 @@
 API_ISOLATED = 3
 
 
+def remove_python_envvars():
+ env = dict(os.environ)
+ # Remove PYTHON* environment variables to get deterministic environment
+ for key in list(env):
+ if key.startswith('PYTHON'):
+ del env[key]
+ return env
+
+
 class EmbeddingTestsMixin:
  def setUp(self):
  here = os.path.abspath(__file__)
@@ -232,7 +241,8 @@ def test_pre_initialization_sys_options(self):
  Checks that sys.warnoptions and sys._xoptions can be set before the
  runtime is initialized (otherwise they won't be effective).
  """
- env = dict(os.environ, PYTHONPATH=os.pathsep.join(sys.path))
+ env = remove_python_envvars()
+ env['PYTHONPATH'] = os.pathsep.join(sys.path)
  out, err = self.run_embedded_interpreter(
  "test_pre_initialization_sys_options", env=env)
  expected_output = (
@@ -591,11 +601,7 @@ def check_global_config(self, configs):
  def check_all_configs(self, testname, expected_config=None,
  expected_preconfig=None, add_path=None, stderr=None,
  *, api):
- env = dict(os.environ)
- # Remove PYTHON* environment variables to get deterministic environment
- for key in list(env):
- if key.startswith('PYTHON'):
- del env[key]
+ env = remove_python_envvars()
 
  if api == API_ISOLATED:
  default_preconfig = self.PRE_CONFIG_ISOLATED