How to create Python Virtual environment within a python script

Question

I am required to make use of my local environment and also use a virtual environment for a specific tool but this tool have dependency issues with my local environment. (I am already aware of how to use a virtualEnv within a script, here I am trying to create a new Virtual Environment within the script.) I want to create a python virtual Environment within a python program while in runtime(Because I have to delete this env at the end of the program). Need this environment to pass to python subprocess as keyword argument env.

I know I can create a virtualEnv using commands as argument to python subprocess. I am looking for some other approach

• Nikaido: Possible duplicate of Activate a virtualenv with a Python script
• Shubham Dadhich: @Nikaidoh No that is for how to use existing virtualEnv, not addressing how to create a new one within the script.
• Tomasz Sabała: Why subprocess is not fulfilling your needs?

Answer 1

To create a virtual env from inside a python script you can use the virtualenv python module.

It pretty much comes down to a single line of code.

import virtualenv
import os
venv_dir = os.path.join(os.path.expanduser("~"), ".venv")
virtualenv.create_environment(venv_dir)

You can then activate this environment by accessing the activate_this.py file in your .venv folder, and install custom packages using pip module.

• Shubham Dadhich: Is there any way to install pip packages using virtualenv?
• Epion: It should be possible with the install_wheel function of this package, which is used internally - however I have never tested whether it works. You can review the code yourself: github.com/pypa/virtualenv/blob/master/virtualenv.py
• Pradhyum R: I believe you can use subprocess.run to run the virtualenv's pip. If I'm not mistaken, it should be in the bin folder.

Answer 2

from venv import create
from os.path import join, expanduser, abspath
from subprocess import run
dir = join(expanduser("~"), "my-venv")
create(dir, with_pip=True)
# where requirements.txt is in same dir as this script
run(["bin/pip", "install", "-r", abspath("requirements.txt")], cwd=dir)