🧠 What are Modules in Python?

A module is a single Python file (.py) that contains definitions (functions, variables, classes) you can use in other programs.

You can:

• Create your own modules

• Import built-in or third-party modules

✅ Example:

import math
print(math.sqrt(16))  # Output: 4.0

📦 What are Packages in Python?

A package is a collection of modules organized in directories that include a special __init__.py file.

✅ Example:

from datetime import datetime
print(datetime.now())

🔹 Ways to Import

import math                    # Import whole module
from math import sqrt         # Import specific function
import math as m              # Import with alias

✅ Built-in Modules in Python (no installation needed)

✅ Commonly Used External Packages (install via pip)

🛠️ Custom Module Example

Create mymodule.py:

def greet(name):
    return f"Hello, {name}!"

Use in another file:

import mymodule
print(mymodule.greet("Abhi"))

📂 Python Package Example (Folder Structure)

my_package/
│
├── __init__.py
├── module1.py
└── module2.py

Use it like:

from my_package import module1

📦 Package Installation via pip

pip install numpy