[Python-checkins] r70742 - in python/branches/py3k/Lib/importlib: _bootstrap.py test/import_/test_path.py

[brett.cannon]

Author: brett.cannon
Date: Mon Mar 30 21:57:15 2009
New Revision: 70742

Log:
Fix importlib.machinery.PathFinder.find_module() to essentially skip over None
entries in sys.path_importer_cache. While this differs from semantics in how
__import__ works, it prevents any implicit semantics from taking hold with
users.


Modified:
   python/branches/py3k/Lib/importlib/_bootstrap.py
   python/branches/py3k/Lib/importlib/test/import_/test_path.py

Modified: python/branches/py3k/Lib/importlib/_bootstrap.py
==============================================================================
--- python/branches/py3k/Lib/importlib/_bootstrap.py	(original)
+++ python/branches/py3k/Lib/importlib/_bootstrap.py	Mon Mar 30 21:57:15 2009
@@ -661,9 +661,10 @@
                 finder = cls._path_importer_cache(entry)
             except ImportError:
                 continue
-            loader = finder.find_module(fullname)
-            if loader:
-                return loader
+            if finder:
+                loader = finder.find_module(fullname)
+                if loader:
+                    return loader
         else:
             return None
 

Modified: python/branches/py3k/Lib/importlib/test/import_/test_path.py
==============================================================================
--- python/branches/py3k/Lib/importlib/test/import_/test_path.py	(original)
+++ python/branches/py3k/Lib/importlib/test/import_/test_path.py	Mon Mar 30 21:57:15 2009
@@ -55,6 +55,25 @@
             self.assert_(path in sys.path_importer_cache)
             self.assert_(sys.path_importer_cache[path] is importer)
 
+    def test_path_importer_cache_has_None(self):
+        # Test that if sys.path_importer_cache has None that None is returned.
+        clear_cache = {path: None for path in sys.path}
+        with util.import_state(path_importer_cache=clear_cache):
+            for name in ('asynchat', 'sys', '<test module>'):
+                self.assert_(machinery.PathFinder.find_module(name) is None)
+
+    def test_path_importer_cache_has_None_continues(self):
+        # Test that having None in sys.path_importer_cache causes the search to
+        # continue.
+        path = '<test path>'
+        module = '<test module>'
+        importer = util.mock_modules(module)
+        with util.import_state(path=['1', '2'],
+                            path_importer_cache={'1': None, '2': importer}):
+            loader = machinery.PathFinder.find_module(module)
+            self.assert_(loader is importer)
+
+
 
 class DefaultPathFinderTests(unittest.TestCase):