Python Packages (original) (raw)

Last Updated : 6 Apr, 2026

Python packages are a way to organize and structure code by grouping related modules into directories.

• A package is essentially a folder that contains an __init__.py file and one or more Python files (modules).
• Allows modules to be easily shared and distributed across different applications.

**Key Components of a Python Package

• **Module: A single Python file containing reusable code (e.g., math.py).
• **Package: A directory containing modules and a special __init__.py file.
• **Sub-Packages: Packages nested within other packages for deeper organization.

Creating and Accessing Packages

1. **Create a Directory: create a folder that will act as the package root.
2. **Add Modules: Inside the directory, add Python files (modules). Each module can contain related functions or classes.
3. **Add __init__.py: add an __init__.py file to the directory. This file tells Python that the directory should be treated as a package.
4. **Create Sub-packages (Optional): One can organize code further by creating subdirectories with their own __init__.py files.
5. **Import Modules: Modules or functions inside the package can be imported using dot notation, for example:

from mypackage.module1 import greet

Example

In this example, we create a package called math_operations to organize mathematical functions. The package contains two sub-packages:

• **basic: addition and subtraction
• **advanced: multiplication and division

Each operation is stored in its own module, which makes the code modular, reusable and easier to maintain.

maths operation package

**math_operations/__init__.py - This file initializes the main package and exposes commonly used functions so they can be imported directly from the package.

Python `

from .calculate import calculate from .basic import add, subtract from .advanced import multiply, divide

`

**math_operations/calculate.py - This module contains a simple function that prints a message indicating that a calculation is being performed.

Python `

def calculate(): print("Performing calculation...")

`

**math_operations/basic/__init__.py - This file initializes the basic sub-package and makes the add and subtract functions available when the sub-package is imported.

Python `

from .add import add from .sub import subtract

`

**math_operations/basic/add.py - This module contains the function for performing addition.

Python `

def add(a, b): return a + b

`

**math_operations/basic/sub.py - This module contains the function for performing subtraction.

Python `

def subtract(a, b): return a - b

`

**math_operations/advanced/__init__.py - This file initializes the advanced sub-package and exposes the multiply and divide functions from their respective modules.

Python `

from .mul import multiply from .div import divide

`

**math_operations/advanced/mul.py - This module contains the function for performing multiplication.

Python `

def multiply(a, b): return a * b

`

**math_operations/advanced/div.py - This module contains the function for performing division.

Python `

def divide(a, b): return a / b

`

Using the Package

Now we can import functions from the package and use them in our program.

Python `

from math_operations import calculate, add, subtract, multiply, divide

Using the placeholder calculate function

calculate()

Perform basic operations

print("Addition:", add(5, 3)) print("Subtraction:", subtract(10, 4))

Perform advanced operations

print("Multiplication:", multiply(4, 2)) print("Division:", divide(10, 2))

`