Modules and Class Related Tips

Treat code as a module

Developing modules in Python is straightforward. Technically, any Python file is a module. If you think you’ve never written a module, just check if you’ve written any Python files. We can import them and use the variables, functions, and classes in other programs. As an example, here’s a file, physics.py, that we may have written to define some useful constants and functions:

# Physics.py
FREE_FALL_ACCELERATION = 9.81
SPEED_OF_LIGHT = 3e8
def emc2(mass):
  return mass * SPEED_OF_LIGHT * SPEED_OF_LIGHT

And here’s another file, main.py, that reuses it:

import physics
mass = float(input("Enter a planet's mass: "))
# User enters 5.9722e24
print(f"The planet's energy is {physics.emc2(mass)} J")

Let’s run the code below.

A useful module is not merely a collection of statements, it needs documentation as well.

It needs a testing facility like the one described below. It also needs a purpose and a concept.

Let modules act independently

A module is a unit of pre-packaged, reusable code. A module typically consists of variable, function, and class definitions and is expected to be imported by another program. There’s nothing wrong with having a fully self-contained module that may be executed as a program, rather than as a part of something else, however. Consider a variation of the module, this. ...