A few days ago Python 3.9.0 has been released and I really wanted to test ist latest features (maybe I will do a separate post to talk about them) without messing my system with another Python version.
To manage my Python versions I've been using pyenv for a while and once configured, it's very easy to install a new Python version.
You should have at least pyenv 1.2.21 if you want to test Python 3.9.0
In case you haven't updated it and you are using MacOS, you can do it with this command:
brew update && brew upgrade pyenv
once installed you should see the latest version:
pyenv --version pyenv 1.2.21
To install Python 3.9.0 you only need
pyenv install 3.9.0:
pyenv install 3.9.0 python-build: use email@example.com from homebrew python-build: use readline from homebrew Downloading Python-3.9.0.tar.xz... -> https://www.python.org/ftp/python/3.9.0/Python-3.9.0.tar.xz Installing Python-3.9.0... python-build: use readline from homebrew python-build: use zlib from xcode sdk Installed Python-3.9.0 to /Users/andrea/.pyenv/versions/3.9.0
Now that the version you want has been installed, you need to tell pyenv you want to use it:
pyenv local 3.9.0 pyenv which python /Users/andrea/.pyenv/versions/3.9.0/bin/python
You can find the rest of the tutorial on my blog https://www.andreagrandi.it/2020/10/10/install-python-with-pyenv-create-virtual-environment-with-specific-python-version/