用特定的python版本制作virtualenv（MACOS）

Question

I installed brew, python3 (default and latest version) and pip3, pyenv.

TensorFlow does not support python3.7 now, so I heard that I should make a virtualenv that runs 3.6 or lower version independently.

I installed python 3.6.7 by pyenv install 3.6.7 but can't make virtualenv -p 3.6.7 (mydir) because 3.6.7 is not in the PATH ( usr/local/bin ).

How can I update my PATH ?

Answer 1

You don't need the executable to be on the PATH. Assuming you want /usr/local/bin/python3.6.7 to be used in the virtual environment,

virtualenv -p /usr/local/bin/python3.6.7 mydir

Updating your PATH is easy:

PATH=/usr/local/bin:$PATH

This will only update it in your current session; you might want to add this to your shell's startup files to make it permanent. This is a common FAQ but depends on a number of factors (your shell, etc) so google for details. Here is one question with several popular variants in the answers: Setting PATH environment variable in OSX permanently

Answer 2

I know that this doesn't answer the question exactly, but for completeness I'd like to add an Anaconda solution. Provided that an Anaconda environment is present on the system, a new Python environment can be created using conda create -n py36 python=3.6 pip . The name py36 can be arbitrarily chosen (could also be eg myenv or tensorflow ), the desired Python version (in this example 3.6) is specified by python=3.6 .

This environment can then be activated using conda activate py36 (or whatever name you assigned in the previous step). Once the environment is active, you can install tensorflow via pip : pip install tensorflow-gpu . To deactivate the current environment and return to the default environment, use conda deactivate . In this way, you don't have to modify PATH variables.

See also this documentation page for more details on the Anaconda environment.