A module is just a set of functions.
def add(a, b): return a + b
A user made module is loaded exactly the same way as the built-in module. The functions defined in the module are used as if they were methods.
from __future__ import print_function import my_calculator print(my_calculator.add(2, 3)) # 5
from __future__ import print_function from my_calculator import add print(add(2, 3)) # 5
We can import specific functions to the current name space (symbol table).