Check if my Python has all required packages

Question

I have a requirements.txt file with a list of packages that are required for my virtual environment. Is it possible to find out whether all the packages mention

Answer 1

If requirements.txt is like :

django
oursql
sys
notexistingmodule

Then the following script will tell you which modules are missing :

#!/usr/bin/python3
fname = 'requirements.txt'
with open(fname, 'r', encoding='utf-8') as fhd:
    for line in fhd:
        try:
            exec("import " + line)
        except:
            print("[ERROR] Missing module:", line)

This would print :

[ERROR] Missing module: notexistingmodule