管理 Python 的多个版本

Question

Ok, I am relatively new to Python (more of a MATLAB / R /Stata user). I previously installed Python on my computer from the Python website. Everything was running smoothly until I had to install Pytorch too. I tried installing it via pip to no avail, so I had to make a new installation of Python but this time with Anaconda.

However, now I have a mess and I can not load Scypi on Anaconda and I can not load Pytorch in the regular Python I have. Having to run them separately is driving me insane. Is there a way that I can merge the two versions together or should I uninstall and stick to only one?

Answer 1

Have you tried pip3 install pytorch? Sometimes Python2 is the main version. To use python 3 pip instead you have to use pip3 install

Answer 2

Besides the solution of virtual environments, if you are on Windows and have the py launcher installed, you could call the specified version of python using py -3 or py -2 or py -3.6 or py 3.9 as required. Or use the 'shebang' line in the python script for *nix.

More about py-launcher and shebang here: https://www.python.org/dev/peps/pep-0397/

Answer 3

Put this in environment.yml file

name: myenv
channels:
  - pytorch
  - anaconda
dependencies:
  - pytorch
  - torchvision
  - torchaudio
  - cpuonly
  - scipy

You can change the name so that it suits your taste.
You should modify dependencies according to the install command provided by https://pytorch.org .
And you can continue after running the following command.

conda activate [your environment name]

But as described in the conda documentation , if you want to use pip, you should install pip for your conda environment and then use it after using conda for as many packages as possible.

This way, you don't need to uninstall your original python. And in regard to merging the two environment, I haven't heard of it and it seems not a good practice if it's possible.