diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/importlib/_bootstrap.py | 8 | ||||
| -rw-r--r-- | Lib/importlib/test/import_/test_meta_path.py | 18 | ||||
| -rw-r--r-- | Lib/test/script_helper.py | 2 | ||||
| -rw-r--r-- | Lib/test/test_threaded_import.py | 2 |
4 files changed, 25 insertions, 5 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index 2f429060d4..b88acc57f9 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -956,8 +956,9 @@ def _resolve_name(name, package, level): def _find_module(name, path): """Find a module's loader.""" - meta_path = sys.meta_path + _IMPLICIT_META_PATH - for finder in meta_path: + if not sys.meta_path: + _warnings.warn('sys.meta_path is empty', ImportWarning) + for finder in sys.meta_path: loader = finder.find_module(name, path) if loader is not None: # The parent import may have already imported this module. @@ -986,8 +987,6 @@ def _sanity_check(name, package, level): raise ValueError("Empty module name") -_IMPLICIT_META_PATH = [BuiltinImporter, FrozenImporter, PathFinder] - _ERR_MSG = 'No module named {!r}' def _find_and_load(name, import_): @@ -1195,3 +1194,4 @@ def _install(sys_module, _imp_module): (SourcelessFileLoader, _suffix_list(2), True)] sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders), _imp.NullImporter]) + sys.meta_path.extend([BuiltinImporter, FrozenImporter, PathFinder]) diff --git a/Lib/importlib/test/import_/test_meta_path.py b/Lib/importlib/test/import_/test_meta_path.py index 3b130c9a13..2f65af99a9 100644 --- a/Lib/importlib/test/import_/test_meta_path.py +++ b/Lib/importlib/test/import_/test_meta_path.py @@ -1,7 +1,10 @@ from .. import util from . import util as import_util +import importlib._bootstrap +import sys from types import MethodType import unittest +import warnings class CallingOrder(unittest.TestCase): @@ -33,6 +36,21 @@ class CallingOrder(unittest.TestCase): with util.import_state(meta_path=[first, second]): self.assertEqual(import_util.import_(mod_name), 42) + def test_empty(self): + # Raise an ImportWarning if sys.meta_path is empty. + module_name = 'nothing' + try: + del sys.modules[module_name] + except KeyError: + pass + with util.import_state(meta_path=[]): + with warnings.catch_warnings(record=True) as w: + warnings.simplefilter('always') + self.assertIsNone(importlib._bootstrap._find_module('nothing', + None)) + self.assertEqual(len(w), 1) + self.assertTrue(issubclass(w[-1].category, ImportWarning)) + class CallSignature(unittest.TestCase): diff --git a/Lib/test/script_helper.py b/Lib/test/script_helper.py index 10ada6d0d1..b09f4bf49e 100644 --- a/Lib/test/script_helper.py +++ b/Lib/test/script_helper.py @@ -1,6 +1,7 @@ # Common utility functions used by various script execution tests # e.g. test_cmd_line, test_cmd_line_script and test_runpy +import importlib import sys import os import os.path @@ -93,6 +94,7 @@ def make_script(script_dir, script_basename, source): script_file = open(script_name, 'w', encoding='utf-8') script_file.write(source) script_file.close() + importlib.invalidate_caches() return script_name def make_zip_script(zip_dir, zip_basename, script_name, name_in_zip=None): diff --git a/Lib/test/test_threaded_import.py b/Lib/test/test_threaded_import.py index 3faa1845e5..bb72ad4054 100644 --- a/Lib/test/test_threaded_import.py +++ b/Lib/test/test_threaded_import.py @@ -126,7 +126,7 @@ class ThreadedImportTests(unittest.TestCase): def test_parallel_meta_path(self): finder = Finder() - sys.meta_path.append(finder) + sys.meta_path.insert(0, finder) try: self.check_parallel_module_init() self.assertGreater(finder.numcalls, 0) |