Python Modules for Absolute Beginners

Modules in Python

When we write a program in Python Interpreter or Python Shell and then exit from Shell, all definitions that we have included in our program get lost. We can’t use those definitions again. While practicing and learning Python, it may not seem as much of a problem, but in certain cases, for example, while working on a project that deals with various long programs, it’s better to just use a text editor and create scripts of py extension.

Now, if we are using the same function in different programs, we won’t have to define it again and again. We can just create a script containing that function and import that script in every program that makes use of that function. These scripts are called modules in Python.

In this module, we will learn about Python modules and cover the following topics:

• What Are Python Modules?
• Why Do We Use Modules in Python?
• Importing Modules in Python
• Built-in Modules in Python

Before we answer the question “What is module in Python?”, let’s look into a practical example that will help us understand the use of modules in Python.
Say, Leon, a software developer was given a task to develop one software. Leon worked very hard for 4 days on Python projects. And finally, after completing the project, he realized that there are some issues with the coding. So now, he needs to do debugging.

Since he wrote the whole code in one file, he is now stressed out with the fact that the code file has become very big, and making changes in that file messes up everything.
To avoid this kind of scenario, Leon decides to divide the project into different parts based on some features or components. Thus, he finishes debugging without messing up the rest of the codes by performing it on a particular part of the code, one at a time.

Similarly, in Python, modules are used to divide the code into smaller parts. In this, we can group similar data which makes the program easier to understand. The module is a simple Python file that can contain (Python functions, python variables, python classes). Modules are processed with two new statements and one important built-in function which are:

• Import: Lets a client obtain a module as a whole
• From: Permits a client to fetch particular names from a module
• Reload: Gives a way to reload a code of module without stopping Python

import <file-name1, file-name2….file-namen>

def intellipaat():
print “Hello intellipaat”

import hello
hello.intellipaat()


Output:
Hello intellipaat

from module-name import atr1,atr2, …atrn

from module-name import *