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🐍 PYTHON NOTES (BASIC TO ADVANCED)

With Definitions & All Topics Covered
Author: Gambhir Jha

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HAND WRITTEN NOTES ;
PYTHON NOTES WRITTEN DOWNLOAD HERE :
1️⃣ INTRODUCTION TO PYTHON

Definition

Python is a high-level, interpreted, general-purpose programming language known for its simple syntax, readability, and wide range of applications such as web development, data science, AI, automation, and software development.

Features

• Easy to learn & write
• Interpreted language
• Platform independent
• Object-Oriented
• Open source
• Large standard library

Applications

• Web Development
• Data Science & AI
• Machine Learning
• Automation & Scripting
• Game Development

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2️⃣ PYTHON INSTALLATION & SETUP

• Install from python.org
• Check version: python --version
• Python IDEs: IDLE, VS Code, PyCharm, Jupyter Notebook

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3️⃣ BASIC SYNTAX & VARIABLES

Definition

A variable is a container used to store data values in memory.

x = 10
name = "Python"

Rules

• No need to declare data type
• Case-sensitive
• Cannot start with number

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4️⃣ DATA TYPES IN PYTHON

Definition

Data types define the type of data stored in a variable.

Built-in Data Types

• int – Integer numbers
• float – Decimal numbers
• complex – Complex numbers
• str – String
• bool – True/False
• list
• tuple
• set
• dict

a = 10
b = 10.5
c = "Hello"

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5️⃣ TYPE CASTING

Definition

Converting one data type into another.

x = int(10.5)
y = str(100)

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6️⃣ OPERATORS

Definition

Operators are symbols used to perform operations.

Types of Operators

• Arithmetic (+ - * / %)
• Relational (== != > <)
• Logical (and or not)
• Assignment (= += -=)
• Bitwise (& | ^)
• Membership (in, not in)
• Identity (is, is not)

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7️⃣ INPUT & OUTPUT

name = input("Enter name: ")
print("Hello", name)

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8️⃣ CONTROL STATEMENTS

Definition

Used to control the flow of execution.

Conditional Statements

• if
• if-else
• elif

if age > 18:
    print("Adult")

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9️⃣ LOOPS IN PYTHON

Definition

Loops are used to execute a block of code repeatedly.

Types

• for loop
• while loop

for i in range(5):
    print(i)

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🔟 JUMP STATEMENTS

• break
• continue
• pass

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1️⃣1️⃣ STRINGS

Definition

A string is a sequence of characters enclosed in quotes.

s = "Python"

String Operations

• Indexing
• Slicing
• Concatenation
• String methods (upper(), lower(), split())

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1️⃣2️⃣ LIST

Definition

A list is an ordered, mutable collection.

list1 = [1, 2, 3]

List Methods

• append()
• insert()
• remove()
• pop()
• sort()

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1️⃣3️⃣ TUPLE

Definition

A tuple is an ordered, immutable collection.

t = (1, 2, 3)

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1️⃣4️⃣ SET

Definition

A set is an unordered collection with no duplicates.

s = {1, 2, 3}

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1️⃣5️⃣ DICTIONARY

Definition

A dictionary stores data in key-value pairs.

d = {"name": "Python", "version": 3}

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1️⃣6️⃣ FUNCTIONS

Definition

A function is a block of reusable code.

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

Types of Functions

• Built-in
• User-defined
• Lambda function

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1️⃣7️⃣ LAMBDA FUNCTION

Definition

Anonymous function written in one line.

x = lambda a: a*a

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1️⃣8️⃣ FILE HANDLING

Definition

Used to read and write files.

File Modes

• r – read
• w – write
• a – append

file = open("test.txt", "r")

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1️⃣9️⃣ EXCEPTION HANDLING

Definition

Handling runtime errors using try-except.

try:
    print(10/0)
except:
    print("Error")

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2️⃣0️⃣ OOPS CONCEPTS

Object-Oriented Programming

Python supports OOPs for code reusability.

Core Concepts

• Class
• Object
• Inheritance
• Polymorphism
• Encapsulation
• Abstraction

class Student:
    def __init__(self, name):
        self.name = name

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2️⃣1️⃣ INHERITANCE

class Child(Parent):
    pass

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2️⃣2️⃣ POLYMORPHISM

One function, many forms.

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2️⃣3️⃣ MODULES & PACKAGES

Definition

A module is a file containing Python code.

import math

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2️⃣4️⃣ REGULAR EXPRESSIONS

Used for pattern matching.

import re

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2️⃣5️⃣ MULTITHREADING

Allows multiple threads to run concurrently.

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2️⃣6️⃣ DATABASE CONNECTIVITY

• SQLite
• MySQL
• MongoDB

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2️⃣7️⃣ ADVANCED PYTHON TOPICS

• Decorators
• Generators
• Iterators
• Virtual Environment
• API Handling
• Web Scraping
• Automation
• Python with AI/ML

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✅ CONCLUSION

Python is a powerful, flexible language suitable for beginners to professionals. Mastering Python basics to advanced concepts opens doors to high-paying careers in technology.

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