How to check if a module is installed in Python and, if not, install it within the code?

Question

I would like to install the modules 'mutagen' and 'gTTS' for my code, but I want to have it so it will install the modules on every computer that doesn't have them, but it won't try to install them if they're already installed. I currently have:

def install(package):     pip.main(['install', package])  install('mutagen')  install('gTTS')  from gtts import gTTS from mutagen.mp3 import MP3 

However, if you already have the modules, this will just add unnecessary clutter to the start of the program whenever you open it.

Answer 1

EDIT - 2020/02/03

The pip module has updated quite a lot since the time I posted this answer. I've updated the snippet with the proper way to install a missing dependency, which is to use subprocess and pkg_resources, and not pip.

To hide the output, you can redirect the subprocess output to devnull:

import sys import subprocess import pkg_resources  required = {'mutagen', 'gTTS'} installed = {pkg.key for pkg in pkg_resources.working_set} missing = required - installed  if missing:     python = sys.executable     subprocess.check_call([python, '-m', 'pip', 'install', *missing], stdout=subprocess.DEVNULL) 

Like @zwer mentioned, the above works, although it is not seen as a proper way of packaging your project. To look at this in better depth, read the the page How to package a Python App.

Answer 2

you can use simple try/except:

try:     import mutagen     print("module 'mutagen' is installed") except ModuleNotFoundError:     print("module 'mutagen' is not installed")     # or     install("mutagen") # the install function from the question