Tweak the handling of the empty string in sys.path for importlib.

brettcannon · brettcannon · commit f58d45c649c1 · 2012-02-16T18:12:00.000-05:00
It seems better to cache the finder for the cwd under its full path
insetad of '' in case the cwd changes. Otherwise FileFinder needs to
dynamically change itself based on whether it is given '' instead of
caching a finder for every change to the cwd.
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
@@ -713,10 +713,12 @@ def _path_importer_cache(cls, path, default=None):
         the default hook, for which ImportError is raised.
 
         """
+        if path == '':
+            path = _os.getcwd()
         try:
             finder = sys.path_importer_cache[path]
         except KeyError:
-            finder = cls._path_hooks(path if path != '' else _os.getcwd())
+            finder = cls._path_hooks(path)
             sys.path_importer_cache[path] = finder
         else:
             if finder is None and default:
diff --git a/Lib/importlib/test/import_/test_path.py b/Lib/importlib/test/import_/test_path.py
@@ -82,7 +82,7 @@ def test_path_importer_cache_empty_string(self):
         with util.import_state(path=[path], path_hooks=[hook]):
             loader = machinery.PathFinder.find_module(module)
             self.assertIs(loader, importer)
-            self.assertIn('', sys.path_importer_cache)
+            self.assertIn(os.getcwd(), sys.path_importer_cache)
 
 
 class DefaultPathFinderTests(unittest.TestCase):
