Port Python virtualenv to another system

Question

I am using many python packages like numpy, bottleneck, h5py, ... for my daily work on my computer. Since I am root on this machine it is no problem to install these package

Answer 1

Having manually compiled VTK and PySide2 for Python36, I have also found myself bending the virtualenv rules.

Just today, I transferred my virtualenv to another system, and to make things easier, I gave it the exact same path that it had on the previous system. However, I did not have the same path for Python on my new system. Fortunately I was able to change the location that the virtualenv was looking for by altering a 'orig-prefix.txt' file located in [VIRTUALENV]/Lib.

The base Python path a virtualenv requires is stored in: [VIRTUALENV]/Lib/orig-prefix.txt

If I recall correctly, the path of the virtualenv itself is embedded in multiple files. Thus, in a case where I needed to relocate the virtualenv to a different path, I just recreated it and copied over everything except for the [VIRTUALENV]/Scripts directory.

This is probably not the way virtualenv is meant to be used, but it does provide a work-around. Also, note that I am doing this in a Windows environment.

Answer 2

You shouldn't move your virtualenv since it is essentially linked to your system python and the binary won't work on other machines.

However... you can export a list of installed packages and install them in another virtualenv through a requirements.txt file.

Basically, what I usually do with most of my projects:

# Generate a requirements file:
pip freeze > requirements.txt

On the new machine:

# This uses virtualenvwrapper, but you can do it without as well
mkproject my_project_name
git clone git://..../ .
pip install -r requirements.txt