Merge with main repo default branch.

1 files changed, 6 insertions, 2 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 5c4d2c6..98361a7 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -419,8 +419,8 @@ def cache_from_source(path, debug_override=None):
     .pyc/.pyo file calculated as if the .py file were imported.  The extension
     will be .pyc unless sys.flags.optimize is non-zero, then it will be .pyo.
 
-    If debug_override is not None, then it must be a boolean and is taken as
-    the value of bool(sys.flags.optimize) instead.
+    If debug_override is not None, then it must be a boolean and is used in
+    place of sys.flags.optimize.
 
     If sys.implementation.cache_tag is None then NotImplementedError is raised.
 
@@ -1669,7 +1669,11 @@ def __import__(name, globals=None, locals=None, fromlist=(), level=0):
         elif not name:
             return module
         else:
+            # Figure out where to slice the module's name up to the first dot
+            # in 'name'.
             cut_off = len(name) - len(name.partition('.')[0])
+            # Slice end needs to be positive to alleviate need to special-case
+            # when ``'.' not in name``.
             return sys.modules[module.__name__[:len(module.__name__)-cut_off]]
     else:
         return _handle_fromlist(module, fromlist, _gcd_import)