Intermediate Python for Scripting Modules and Packages

Learning objective: By the end of this lesson, students will understand how to import and use modules in Python.

Using built-in modules

Python comes with a rich collection of built-in modules that provide a wide range of functionality out of the box. These modules are part of the Python Standard Library and can be imported directly without any additional installation.

Some commonly used built-in modules include:

• math: Provides mathematical functions and constants.
• random: Generates pseudo-random numbers and provides random-related utilities.
• datetime: Handles date and time operations.
• os: Provides functions for interacting with the operating system.
• sys: Provides access to system-specific parameters and functions.

In addition to built-in modules, you can create your own custom modules to organize and reuse your code. Custom modules can be shared across different projects or with other developers.

Importing modules from packages

When importing modules from packages, you can use various import styles depending on your needs. There are many different input styles, but we’ll look at a couple of the most common ones:

Importing an entire package

The most straightforward way to import a package is to use the import statement followed by the package name. This imports the entire package, allowing you to access its functionality.

Syntax:

import package_name

Example:

intermediate_python.py

import math

This imports the entire math package, allowing you to access its functions and constants using the math. prefix. For example, to calculate the square root of a number, you would use:

intermediate_python.py

result = math.sqrt(16)
print(result)  # Output: 4.0

Import a specific module from a package

Syntax:

from package_name import module_name

Example:

intermediate_python.py

from math import sqrt

This imports the sqrt function from the math module, allowing you to use it directly without prefixing it with math..

By using this syntax, to calculate the square root of a number, you can use sqrt() directly:

intermediate_python.py

result = sqrt(25)
print(result)  # Output: 5.0

Access the constant pi in the math module. Print the value of pi to the console.