Getting Started with Python (Part 11): Using Modules

Using Modules

In this article, you’ll learn about modules in Python.

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What Is a Module?

A module is a separate file (program) that contains Python code.

By importing and combining various modules, you can build applications more efficiently.

In Python, files that you create yourself can also be used as modules.

In addition, Python provides many built-in standard modules.

Modules developed by third parties are called third-party modules.

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Importing a Module

You can import a module using the import statement.

import module_name

Here, let’s try using one of Python’s standard modules, random.

As the name suggests, it is used to generate random values.

import random

# Random float between 0.0 and 1.0
print(random.random())  # 0.8189799827412905

# Random integer between 1 and 10
print(random.randint(1, 10))  # 2

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Importing a Specific Part of a Module

By using from, you can import only a specific part of a module.

In the following example, we import only the random function from the random module.

from random import random

# Only the random function is imported
print(random())  # 0.38405708986017906

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Giving a Module an Alias

By using as, you can give an imported module or function an alias.

This is useful to avoid name conflicts with other modules.

from random import random as r

# It doesn’t get much shorter than this!
print(r())  # 0.941147291147711

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Commonly Used Standard Modules

Here are some commonly used standard modules in Python.

Module	Purpose	Example	Description
os	OS operations	os.listdir(".")	Get a list of files in the current directory
pathlib	File paths	Path("test.txt").exists()	Check if a file exists
time	Time control	time.sleep(1)	Wait for 1 second
datetime	Date and time	datetime.datetime.now()	Get the current date and time
random	Random numbers	random.random()	Float between 0.0 and 1.0
math	Math functions	math.sqrt(9)	Square root (3.0)

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Popular Third-Party Modules

Next, let’s look at some popular third-party modules.

To use these modules, you need to install them separately using pip.

Module	Use Case	Popularity
numpy	Fast numerical computation, arrays	★★★★★
pandas	Data analysis, tabular data processing	★★★★★
matplotlib	Data visualization, plotting	★★★★★
django, flask, fastapi	Web apps and APIs	★★★★★
requests	Web API calls, HTTP communication	★★★★★
sqlalchemy	Database operations	★★★★★
beautifulsoup	Web scraping	★★★★★
Pillow	Image editing and processing	★★★★★
scikit-learn, xgboost, catboost	Machine learning	★★★★★

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What’s Next?

Thank you for reading!

In the next article, we’ll learn about classes.

The next title will be:

“Getting Started with Python (Part 9): Using Classes”

Stay tuned! 🚀