Modules in Python 📦🐍

A module in Python is a file containing Python code (functions, classes, or variables) that can be imported and reused in other programs.

🔹 Modules help organize code into smaller, reusable pieces.
🔹 Any Python file (.py) is a module that can be imported into another script.

1️⃣ Creating and Importing a Module
✅ Creating a Module (my_module.py)

# my_module.py
def greet(name):
return f"Hello, {name}!"

pi = 3.14159
✅ Importing the Module

import my_module

print(my_module.greet("Alice")) # Hello, Alice!
print(my_module.pi) # 3.14159
🔹 Syntax: import module_name
🔹 Access module functions/variables using dot notation (module_name.function()).

2️⃣ Different Ways to Import Modules

✅ 1. Importing the Entire Module

import my_module

print(my_module.greet("Bob")) # ✅ Uses dot notation
✅ 2. Importing Specific Functions/Variables

from my_module import greet, pi

print(greet("Charlie")) # No need for dot notation
print(pi) # 3.14159
🔹 No need for module_name. prefix when using from module import function.

✅ 3. Importing with an Alias (as)

import my_module as mm

print(mm.greet("David")) # Uses alias instead of full module name
✅ 4. Importing Everything (*) ❌ (Not Recommended)

from my_module import *

print(greet("Eve")) # Works without dot notation
print(pi)
🔹 from module import * imports everything, which can cause namespace conflicts.

3️⃣ Built-in Modules in Python

Python comes with many built-in modules (standard library) that provide extra functionality.

✅ Examples of Built-in Modules


import math
import random
import datetime

print(math.sqrt(16)) # 4.0
print(random.randint(1, 10)) # Random number between 1-10
print(datetime.datetime.now()) # Current date and time
🔹 Check all built-in modules using:


help("modules")

4️⃣ Finding Module File Path

To check where a module is located:


import math
print(math.__file__) # Shows the location of math module

5️⃣ Running a Module as a Script (__name__ == "__main__")

Modules can be used both as an import and as an independent script.


# my_module.py
def greet(name):
return f"Hello, {name}!"

if __name__ == "__main__":
print(greet("Main Script"))
🔹 If my_module.py is run directly, it prints "Hello, Main Script!".
🔹 If my_module.py is imported, the if __name__ == "__main__" block won't execute.

Summary


Import Method Syntax Usage

Import entire module import module_name module_name.function()

Import specific items from module_name import function function() (no module prefix)

Import with alias import module_name as alias alias.function()

Import everything from module_name import * ❌ Not recommended (namespace conflicts)

    Date: 2025-03-24 00:00:00.000000