If I have a venv path, how can I find out if a Python module is installed inside that venv?

I normally use importlib.util.find_spec. But this only works for the current venv that is active and does not work if I have a different venv path.

from importlib.util import find_spec

if find_spec('numpy'):
    # Do something

If I have a venv path, how can I find out if a Python module is installed inside that venv?

I normally use importlib.util.find_spec. But this only works for the current venv that is active and does not work if I have a different venv path.

from importlib.util import find_spec

if find_spec('numpy'):
    # Do something

• python
• python-importlib
• venv

• 2 One way (the most obvious one) is to run your code and if you get import errors then you know you are missing imports. I think you may need to describe your use case, or what problem you are solving. For instance, you could create a requirements.txt file based on your working development code just make sure when you create new venvs for your project you set it up correctly, or if you have a deployment process it becomes part of that process. – topsail Commented 2 days ago
• i would go to folder with venv, activate venv, and run pip list (with some grep to filter module) to check if it has this module. Eventually instead of activing venv I would use venv/bin/python -m pip list to cech modules in this venv. And this doesn't need Python but bash/shell script. In Python it may need to run with subprocess.run() – furas Commented yesterday

1 Answer 1

import sys
import importlib.util
import os
from pathlib import Path

def is_module_installed_in_venv(module_name, venv_path):
    venv_python_lib_path = Path(venv_path) / 'lib'
    for python_dir in venv_python_lib_path.iterdir():
        if python_dir.name.startswith('python'):
            site_packages_path = python_dir / 'site-packages'
            break
    
    if not site_packages_path.exists():
        return False
    
    sys.path.insert(0, str(site_packages_path))

    module_spec = importlib.util.find_spec(module_name)
    
    sys.path.pop(0)
    
    return module_spec is not None

venv_path = '/home/user/anaconda3/envs/env_name/' 
module_name = 'numpy'

if is_module_installed_in_venv(module_name, venv_path):
    print("do something")

this works , make sure to include the full path