Chapter 7: Python Modules & Packages

Exercise 1

Create Your First Module

Create a simple math utility module with basic functions.

                        # Create a file named math_utils.py

                        # Add functions for:

                        # - add(a, b): returns sum of a and b

                        # - subtract(a, b): returns a minus b

                        # - multiply(a, b): returns a times b

                        # - divide(a, b): returns a divided by b

Create a new file named math_utils.py

Add the four arithmetic functions

Test the module by importing it in another script

Call each function with sample values

Print the results

Exercise 2

Different Import Methods

Practice different ways to import and use modules.

                        # Using the math_utils module from Exercise 1:

                        # 1. Import the entire module

                        # 2. Import specific functions

                        # 3. Import with an alias

                        # 4. Use each import method

Import the entire module: import math_utils

Import specific functions: from math_utils import add

Import with alias: import math_utils as mu

Call functions using each import method

Compare the different syntax approaches

Exercise 3

Create a Package

Create a Python package with multiple modules.

my_package/
├── __init__.py
├── string_utils.py
└── number_utils.py

Create a directory named my_package

Add an __init__.py file (can be empty)

Create string_utils.py with string manipulation functions

Create number_utils.py with number-related functions

Import and use the package from another script

Exercise 4

Explore Standard Library Modules

Use Python's built-in modules for common tasks.

                        # Use these standard library modules:

                        # - math: mathematical functions

                        # - datetime: date and time operations

                        # - random: generate random numbers

                        # - os: operating system interfaces

Use math.sqrt() to calculate square roots

Use datetime to get current date and time

Use random to generate random numbers

Use os to get the current working directory

Print results from each module usage

Exercise 5

Module Aliases and Selective Import

Practice using aliases and importing specific elements.

                        # Practice these import techniques:

                        # 1. Import numpy with alias np

                        # 2. From math import pi, sqrt

                        # 3. From datetime import date as d

                        # 4. Use each imported element

Import numpy as np (if installed)

Selectively import pi and sqrt from math

Import date from datetime with alias

Use each imported element in calculations

Note the differences in usage syntax

Hint

If numpy is not installed, you can use pip to install it: pip install numpy

Exercise 6

Install and Use External Packages

Use pip to install and work with external packages.

                        # Install and use these popular packages:

                        # - requests: HTTP requests

                        # - pandas: data manipulation

                        # - matplotlib: data visualization

                        # (Install with: pip install package_name)

Install requests using pip

Make a simple HTTP GET request

Install pandas and create a simple DataFrame

Install matplotlib and create a simple plot

Note the installation process and usage

Hint

You may need to use virtual environments for package management in larger projects.

Exercise 7

Explore Module Contents

Use Python's built-in functions to explore modules.

                        # Use these exploration techniques:

                        # - dir(module): list all attributes

                        # - help(module): show documentation

                        # - module.__doc__: module documentation

                        # - module.__file__: location of module

Import the math module

Use dir() to list all available functions

Use help() to read documentation for specific functions

Access the module's __doc__ attribute

Find where the module is located using __file__

Exercise 8

Create an init.py File

Customize package initialization with __init__.py.

                        # In your package's __init__.py:

                        # 1. Import key functions from modules

                        # 2. Define __all__ to control exports

                        # 3. Add package-level documentation

                        # 4. Initialize package-level variables

Open the __init__.py file in your package

Import important functions from your modules

Define __all__ to specify what gets imported with *

Add a docstring describing the package

Test the package import with from package import *

Exercise 9

Comprehensive Module Project

Create a complete utility package with multiple modules.

utilities/
├── __init__.py
├── math_ops.py
├── string_ops.py
├── date_ops.py
└── io_ops.py

Create a utilities package with the structure above

Add appropriate functions to each module

Customize the __init__.py to import key functions

Create a test script that uses all modules

Demonstrate the package's functionality