from Hacker News

PEP 486 – Make the Python Launcher aware of virtual environments (2015)

by okl on 2/19/25, 11:03 AM with 8 comments

• by zahlman on 2/19/25, 1:05 PM

  Huh. Come to think of it, when I was on Windows (through 2021) I got used to using `python` rather than `py` while using venvs, even though it was apparently no longer necessary after I upgraded from Python 3.4. This announcement totally missed me. But also it was easier to internalize "always use venvs, and always run `python`, and that way you won't have to change the instructions for Linux/Mac". And that worked out beautifully.

  But the launcher does have value. Mainly because of how Windows handles the PATH and how it wants C:\Program Files to be organized; but there are enough fringe benefits that a core dev wants to bring it to Linux/Mac too (https://github.com/brettcannon/python-launcher).

• by FloatArtifact on 2/22/25, 4:52 PM

  It seems to me py launcher could have done the same thing as uv such as downloading and setting up python and managing virtual environments.

• by westurner on 3/2/25, 4:50 AM

  pip used to support virtualenvs.

  pip 0.2 (2008) https://pypi.org/project/pip/0.2/ :

  > pip is complementary with virtualenv, and it is encouraged that you use virtualenv to isolate your installation.

  https://pypi.org/project/pip/0.2/#using-pip-with-virtualenv :

    pip install -E venvpath/ pkg1 pkg2
  

  When was the -E <virtualenv> flag removed from pip and why?

    pip install --help | grep "\-E"