🔸 What is a Package?

• A package is a folder that contains Python files (modules).
• It helps you organize your code.
• You can reuse the code in many projects.

✅ Why Use Packages?

• Keeps your code clean and structured
• Makes code reusable
• Easy to share with others

🧳 Step-by-Step: Create Your Own Python Package

🔹 Step 1: Create Folder Structure

Let’s say you want a package named mymath.

mymath/
│
├── __init__.py
├── add.py
└── multiply.py

✅ __init__.py makes this folder a package.

🔹 Step 2: Write Module Files

📄 add.py:

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

📄 multiply.py:

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

📄 __init__.py:

from .add import add
from .multiply import multiply

🔹 Step 3: Use the Package in Your Code

Create a new file outside the folder (for example: main.py)

📄 main.py:

from mymath import add, multiply

print(add(2, 3))        # Output: 5
print(multiply(2, 3))   # Output: 6

✅ Now your package is working!

🔹 Step 4 (Optional): Add __all__ in __init__.py

This helps when you use from mymath import *

__all__ = ['add', 'multiply']

✅ Practice Time

Q1: Create a package called greet with:

• hello.py: hello(name) → prints “Hello, [name]”
• bye.py: bye(name) → prints “Goodbye, [name]”

Answer:

Folder:

greet/
├── __init__.py
├── hello.py
└── bye.py

📄 hello.py:

def hello(name):
    print(f"Hello, {name}")

📄 bye.py:

def bye(name):
    print(f"Goodbye, {name}")

📄 __init__.py:

from .hello import hello
from .bye import bye

Use it in main.py:

from greet import hello, bye

hello("John")
bye("John")

📦 Bonus: Make it Installable (Advanced)

To share with others (like on PyPI), create a setup.py:

from setuptools import setup, find_packages

setup(
    name='mymath',
    version='0.1',
    packages=find_packages()
)

Then run:

python setup.py install

🧾 Summary

🧠 Final Tip:

You can create your own Python tools using packages.
Perfect for organizing large projects!