pip install jsmin

function foo() {
    console.log('hi')
}

$ python -m jsmin myfile.js

function foo(){console.log('hi')}

# -*- coding: utf-8 -*-
from jsmin import jsmin

with open('myfile.js') as js_file:
    minified = jsmin(js_file.read())
    print(minified)
    
# function foo(){console.log('hi')}