Could not create Python virtual environment

Question

Dawid Kmak 2021-3-31

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/789104-could-not-create-python-virtual-environment

回答： Ricardo Antunes 2023-7-6

I'm getting error while using rosinit. When i was using python 3.8 i got:

Launching ROS Core...

Could not find Python version 2.7 on your system. Use pyenv function to set the path

to the Python 2.7 executable.

After switching to 2.7 i got this error:

Could not create Python virtual environment. 'C:\Users\User

Name\AppData\Roaming\MathWorks\MATLAB\R2021a\ros1\win64\venv\Scripts\python.exe' is

not found. Verify installation of Python in your system and re-create the Python

virtual environment.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Benjamin William Brokaw 2021-4-22

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/789104-could-not-create-python-virtual-environment#answer_682155

在 MATLAB Online 中打开

I was struggling with this problem for so long and it seems we are the only ones having this issue.

What ended up working for me was pip installing virtualenv and then creating a virtual python enviornment with 'virtualenv tmpenv' .

Next I coppied the contents of tmpenv over to AppData\Roaming\MathWorks\MATLAB\R2021a\ros1\win64\venv\

I had to create this outside of \venv\ because of the way the createOrGetLocalPython.m script works. There is a command to create the directory win64/venv/temp that will error out if the parent folders already exist.

I beleive the culprit is line 135 in createOrGetLocalPython.m:

[stat, res] = system(['"' pyexec '" ' fullfile(tempPythonExtractDir,'virtualenv-16.6.1','virtualenv.py') ' --no-setuptools --no-pip --no-wheel ' pyenvDir '  --system-site-packages']);

This line should setup the env for us, but in my case it was returning success but not actually creating it.

Hope this helps!

3 个评论
显示 1更早的评论隐藏 1更早的评论

Auwal SHEHU 2022-3-20

Hi Robert,

I have similar issue. Please I need your help.

Auwal SHEHU 2022-3-20

Creating a Python virtual environment...Done.

Error using ros.internal.createOrGetLocalPython

Could not create Python virtual environment.

in Matlab

请先登录，再进行评论。

Answer 2

Murat Belge 2022-6-29

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/789104-could-not-create-python-virtual-environment#answer_996705

ROS Toolbox creates a Python virtual environment in user's prefdir by default. If your user name contains spaces and this gets reflected in prefdir, this will create issues with Python virtual environment generation and later on with custom message generation, etc. To work around this, set 'MY_PYTHON_VENV' environment variable to a directory without spaces and run ros.internal.createOrGetLocalPython function as in the following:

>> setenv('MY_PYTHON_VENV','C:\temp\venv')

>> ros.internal.createOrGetLocalPython(true)

This will use 'C:\temp\venv' as the root directory for Python virtual environment.