[Python-Dev] Python environment registration in the Windows Registry (original) (raw)

eryk sun eryksun at gmail.com
Wed Feb 3 12:23:36 EST 2016

On Wed, Feb 3, 2016 at 10:46 AM, Steve Dower <steve.dower at python.org> wrote:

sys.path.extend(readsubkeys(fr'HKCU\Software\Python\PythonCore{sys.winver}\PythonPath**')) sys.path.extend(readsubkeys(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.

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