What are my options for installing Python alpha & beta releases with or alongside conda on Windows?

Question

Closely related to Can I conda install an alpha or beta version of Python? but that question is about a specific version in conda-forge. If a Python release (e.g. 3.10.0b1) is available for download via https://www.python.org/download/pre-releases/ but not in the main anaconda or any other conda channel yet, what are my best bets for using it?

• Open an issue at conda-forge?
• Some generic conda install script to run the python installer inside an environment?
• Something else...

Particularly with alpha/beta releases of Python, I'd like the protection of a conda environment for my installation. I'm worried about using the standard Python installer now as it might not play nicely, but maybe there are some mitigation measures I can take?

Answer 1

pyenv is probably the best way to manage Python installations (not to be confused with Python virtual environments). It can easily install and access alpha and beta versions of Python, or whatever other previous versions have been published.

Unfortunately, pyenv does not work in Windows outside the Windows Subsystem for Linux. Fortunately, you can use pyenv-win, which is a port of pyenv for Windows, and is recommended by the authors of pyenv. To install it, follow their installation instructions.

Once you've got it installed, you can run the following to install Python 3.10.0b1:

pyenv install 3.10.0b1
pyenv global 3.10.0b1

Note that alpha/beta releases are not permanent, so when you actually run these commands 3.10.0b1 may no longer be available. You can run pyenv update to update pyenv, which will inform it of the currently available versions. pyenv install 3.10.<TAB><TAB> will show you which versions of Python 3.10 can be installed.

You can test it by running:

python -V

You should get an output of Python 3.10.0b1 if everything is in order.

To use Conda with pyenv, see this answer: https://stackoverflow.com/a/58045984/5946921