Python

Create your own Python Modules

Python is a multi-purpose, high level, and dynamic programming language. It provides many built-in modules and functions to perform various types of tasks. Aside from that, we can also create our own modules using Python. A module is like a library in Java, C, C++, and C#. A module is usually a file that contains functions and statements. The functions and statements of modules provide specific functionality. A Python module is saved with the .py extension. In this article, we will learn to create our own Python modules.

A module is typically used to divide the large functionality into small manageable files. We can implement our most used functions in a separate module, and later on, we can call and use it everywhere. The module’s creation promotes reusability and saves a lot of time.

Create Python modules

To create a Python module, open a Python script, write some statements and functions, and save it with .py extension. Later on, we can call and use these modules anywhere in our program.

Let’s create a new module named “MathOperations”. This module contains functions to perform addition, subtraction, multiplication, and division.

#creating MathOperation module

#the module provides addition, subtraction, multiplication, and division functions

 

#all the functions take two numbers as argument

 

#creating addition function

def addition(num1,num2):

    return num1+num2

 

#creating subtraction function

def subtraction(num1,num2):

    return num1-num2

 

#creating multiplication function

def multiplication(num1,num2):

    return num1*num2

 

#creating division function

def division(num1,num2):

    return num1/num2

Now, we can call this module anywhere using the import command, and we can use these functions to perform the related tasks. There is no need to write the code again and again for performing addition, subtraction, multiplication, and division operations.

Call your module

Let’s call this module in our other Python script by using the import command. Check out this article (https://linuxhint.com/python_import_command/) to learn more about the Python import command.

import MathOperation

#calling addition function from MathOperation module

#the function is called by using the module name

print("The sum is:",MathOperation.addition(10,4))

 

#calling subtraction function

print("The difference is: ",MathOperation.subtraction(100,34))

 

#calling multiplication function

print("The multiplication is: ",MathOperation.multiplication(4,3))

 

#calling division function

print("The division result is:",MathOperation.division(200,5))

Output

Calling the module variables

We can also declare the variables in our self-created Python modules, assign values to those variables, and call them in our Python script. The modules can also contain dictionaries, lists, etc.

#creating variables

num1 = 10

num2 = 20

 

#creating the student list

student = ['John','Mark','Taylor','David']

#creating the student dictionary

std_dict = {'name':'Ali','age':12,'email':'ali@xyz.com'}

Now let’s call the variables and objects in other Python script.

#import the module

import MathOperation

#calling the variable num1

print("The num1 value is:",MathOperation.num1)

 

#calling the variable num2

print("The num1 value is:",MathOperation.num2)

 

#calling the student list

print("The num1 value is:",MathOperation.student)

 

#calling the student's list items

print(MathOperation.student[0])

print(MathOperation.student[1])

print(MathOperation.student[2])

print(MathOperation.student[3])

 

#printing the student dictionary

print(MathOperation.std_dict)

 

#calling the student's dictionary items

print(MathOperation.std_dict['name'])

print(MathOperation.std_dict['age'])

print(MathOperation.std_dict['email'])

Output

The output shows that we have successfully accessed the variables and functions from the “MathOperation” module.

List all the functions and variables of a module

Python provides a built-in dir() function, which lists down the names of all functions and variables that are present in a particular module. Let’s use the dir() function to list down the names of functions and variables of the “MathOperation” module.

These our functions and variables that are created in our “MathOperation” module.

#creating MathOperation module

#the module provides addition, subtraction, multiplication, and division functions

 

#all the functions take two numbers as argument

 

#creating addition function

def addition(num1,num2):

    return num1+num2

 

#creating subtraction function

def subtraction(num1,num2):

    return num1-num2

 

#creating multiplication function

def multiplication(num1,num2):

    return num1*num2

 

#creating division function

def division(num1,num2):

    return num1/num2

 

#creating variables

num1 = 10

num2 = 20

 

#creating the student list

student = ['John','Mark','Taylor','David']

#creating the student dictionary

std_dict = {'name':'Ali','age':12,'email':'ali@xyz.com'}

Now let’s call the dir() function in our Python script.

#importing the module

import MathOperation

#using the dir() function

print(dir(MathOperation))

Output

Conclusion

Although Python provides many built-in modules and functions to perform some specific task, we can also create our own Python modules. A Python module contains functions and variables. The Python modules are saved with the .py extension. This article explains the creation of your own Python modules with the help of simple examples.

About the author

Kamran Sattar Awaisi

Kamran Sattar Awaisi

I am a software engineer and a research scholar. I like to write article and make tutorial on various IT topics including Python, Cloud Computing, Fog Computing and Deep Learning. I love to use Linux based operating systems.