通过 virtualenv 在 Mac 上安装旧版本的 Python

Question

I need to install a certain package, for which the developers suggest Python 3.5 , since they don't support 3.7 yet. I am running Mac OS Mojave 10.14.2 and my Python version is 3.7.1 .

I have come across methods to switch between Python 2.x and 3.x using Virtualenv , such as below:

virtualenv -p python2 myenv

virtualenv -p python3 myenv

However, is it even possible to have a specific version of Python, that too one older than I have already installed on my system?

Answer 1

Yes, it is possible to have multiple versions of Python installed on OSX. Each one installs to a different path. You can't have multiple 'python3' executables in your path -- but if you use the absolute path then it'll work out fine.

You can go download the OSX version of Python 3.5 (which will install itself as python3.5 somewhere), and then create a virtualenv via

virtualenv -p /absolute/path/to/python3.5 myenv

Answer 2

you can use

python -m virtualenv <env_name> --python=<full-path-to-python-exectuable-file-and-exe-file>

here <full-path-to-python-exectuable-file-and-exe-file> add python3.5 which you have downloaded