Example of dynamic loading in python

cat.py

class Cat(object):
    def make_sound(self):
        print("Cat says Meow")


    def hide(self, num):
        print("Regular cat is hiding for %s secs"% num)


class BrownCat(object):
    def make_sound(self):
        print("Brown Cat says Meow")

    def hide(self, num):
        print("Brown cat is hiding for %s secs"% num)

main_file.py

import importlib

def main():

    #module name without the .py extension
    cat_module_name="cat"
    #Cat class in cat module
    cat_cls_name="Cat"
    #BrwonCat class in cat module
    brown_cat_cls_name="BrownCat"

    #get cat module
    cat_module=importlib.import_module(cat_module_name)
    #create cat instance
    cat_inst = getattr(cat_module, cat_cls_name)()
    #create brown cat instance
    brow_cat_inst = getattr(cat_module, brown_cat_cls_name)()

    #call cat methods
    cat_inst.make_sound()
    cat_inst.hide(5)

    #call brown cat methods
    brow_cat_inst.make_sound()
    brow_cat_inst.hide(10)




if __name__ == "__main__":
    main()

output

Cat says Meow
Regular cat is hiding for 5 secs
Brown Cat says Meow
Brown cat is hiding for 10 secs