rollback 005fd1fe31ab (see #14609 and #14582)

Being able to overload a sys.module entry during import of a module was broken
by this changeset.

1 files changed, 6 insertions, 10 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 415c488..142461a 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -984,12 +984,12 @@ def _find_and_load(name, import_):
     loader = _find_module(name, path)
     if loader is None:
         raise ImportError(_ERR_MSG.format(name), name=name)
-    elif name in sys.modules:
-        # The parent module already imported this module.
-        module = sys.modules[name]
-    else:
-        module = loader.load_module(name)
+    elif name not in sys.modules:
+        # The parent import may have already imported this module.
+        loader.load_module(name)
         verbose_message('import {!r} # {!r}', name, loader)
+    # Backwards-compatibility; be nicer to skip the dict lookup.
+    module = sys.modules[name]
     if parent:
         # Set the module as an attribute on its parent.
         parent_module = sys.modules[parent]
@@ -1088,11 +1088,7 @@ def __import__(name, globals={}, locals={}, fromlist=[], level=0):
         # Return up to the first dot in 'name'. This is complicated by the fact
         # that 'name' may be relative.
         if level == 0:
-            index = name.find('.')
-            if index == -1:
-                return module
-            else:
-                return sys.modules[name[:index]]
+            return sys.modules[name.partition('.')[0]]
         elif not name:
             return module
         else: