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  • Python programmers: Watch out for Win10 version 1903

    Home Forums AskWoody blog Python programmers: Watch out for Win10 version 1903

    This topic contains 4 replies, has 4 voices, and was last updated by  Norio 4 weeks, 1 day ago.

    • Author
    • #2005337 Reply

      Da Boss

      We had a report a few hours ago from MartinPurvis that performing an in-place upgrade from Win10 version 1803 to version 1903 clobbered Python: Turns
      [See the full post at: Python programmers: Watch out for Win10 version 1903]

    • #2005342 Reply

      AskWoody Plus

      Back on the SuperUser site, Ramhound says:

      This was intended behavior. Microsoft added this behavior with 1903 because they recognized developers struggle getting Python installed. I read about this change but I don’t recall where I read it.

      I can’t find the original description Ramhound describes. Can anybody out there point me to it?

      He found it three posts further down:

      Who put Python in the Windows 10 May 2019 Update?

      Windows 10 Pro Version 1909 (Group ASAP)

      1 user thanked author for this post.
    • #2005406 Reply


      Who exactly has problems installing Python?  As a developer?  I see some mention of the Store being utilized as a package manager (which it isn’t), but if any dev wanted to have a package manager on Windows they’d use Nuget or Git.

      I only see this causing problems, especially if it doesn’t check for previous installs of Python.

    • #2005522 Reply


      This shouldn’t cause any problems for users using python as intended. You’re supposed to use the py.exe launcher. You can set it to associate with .py files, which causes python programs to launch properly according to their shebang just like on Unix. py -3 opens the correct version of python 3, etc.

      On Windows, launching python from the command line with “python” has never worked properly like it does on unix. Why? Because there aren’t separate python3 and python2 executables. They’re both named python.exe so whichever one is earlier in your PATH gets launched. This is unusable, hence the py.exe launcher which also handles shebangs.

    • #2005943 Reply

      AskWoody Plus

      There is another potential issue for Python-on-Windows users involving environment variables and paths.
      On the blog “not quite minimalistic enough” (, the author notes that:

      OH NO, NOT AGAIN …

      The Python-on-Windows people are at it again. This time they have deliberately broken os.path.expanduser() in 3.8.
      Until 3.7, expanduser() treated a tilde at the front of the path given to it the same as a *ix shell, i.e. ‘~/’ was replaced by the current user’s home directory, and ‘~user/’ with that of user user.

      [Moderator edit] please use a precis of other’s work, not the whole thing.

    Please follow the -Lounge Rules- no personal attacks, no swearing, and politics/religion are relegated to the Rants forum.

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