Could not create Python virtual environment

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Dawid Kmak
Dawid Kmak 2021 年 3 月 31 日
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.

回答 (2 件)

Benjamin William Brokaw
Benjamin William Brokaw 2021 年 4 月 22 日
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','') ' --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 件のコメント
Auwal SHEHU 2022 年 3 月 20 日
Creating a Python virtual environment...Done.
Error using ros.internal.createOrGetLocalPython
Could not create Python virtual environment.
in Matlab


Murat Belge
Murat Belge 2022 年 6 月 29 日
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.
  1 件のコメント
Hari Krishna Kakarla
Hari Krishna Kakarla 2022 年 7 月 2 日
Minor update to the above Answer. For R2021a relase, The environment variable that has to be set is 'MY_PYTHON2_VENV'.
For the Release older than R2022a, Please execute these commands below and then run ros.internal.createOrGetLocalPython(true) function:
>> setenv('MY_PYTHON2_VENV','C:\temp\venv')
>> ros.internal.createOrGetLocalPython(true)
From R2022a onwards:
>> setenv('MY_PYTHON_VENV','C:\temp\venv')
>> ros.internal.createOrGetLocalPython(true)





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