On Wed, Feb 3, 2016 at 10:46 AM, Steve Dower
sys.path.extend(read_subkeys(fr'HKCU\Software\Python\PythonCore\{sys.winver}\PythonPath\**')) sys.path.extend(read_subkeys(fr'HKLM\Software\Python\PythonCore\{sys.winver}\PythonPath\**'))
It seems like a bug (in spirit at least) that this step isn't skipped for -E and -I (Py_IgnoreEnvironmentFlag, Py_IsolatedFlag).
I haven't looked into pywin32's use of this recently - I tend to only use Christoph Gohlke's wheels that don't register anything.
I install the pypiwin32 wheel using pip, which uses pypiwin32.pth: # .pth file for the PyWin32 extensions win32 win32\lib Pythonwin import os;os.environ["PATH"]+=(';'+os.path.join(sitedir,"pypiwin32_system32")) This is different from a PythonPath subkey in a couple of respects. The paths listed in .pth files are appended to sys.path instead of prepended. They also don't get added when run with -S or for a venv environment that excludes site-packages.