Use of python pip packages and python virtual environments in guix

[Timothee Mathieu]

Hello, 

I am new to guix, and I would like to use the containers in order to have 
reproducible development environments for python. 
A lot of the packages that I use are not on guix yet and it would be too long 
and a lot of work to actually put them as packages, hence I want to 
use both guix shell -C for container in order to be able to fix the C libraries 
and a python virtual environment inside the container to fix the python 
versions. 
However, if I do that, I need to set the LD_LIBRARY_PATH to /lib and use guix 
shell -F otherwise the python libraries do not find the shared libraries. 

I saw here: https://issues.guix.gnu.org/25072 that my solution was not good 
(they say it is a hacking) and I was wondering what is good practice to use 
python virtual environments in guix. 

I think having a way to handle this would be a great tool for producing 
reproducible article by providing a middle ground between full guix packages 
(which is time consuming) and what is done actually with python pip. 

Thanks.