What is Python Programming Language? Complete Guide 2026

What is Python?

Python is a high-level, interpreted, general-purpose programming language created by Guido van Rossum and first released in 1991. It emphasizes code readability and simplicity, allowing developers to express concepts in fewer lines of code than languages like C++ or Java.

Python supports multiple programming paradigms including object-oriented, procedural, and functional programming. It is dynamically typed and garbage-collected, making it beginner-friendly while remaining powerful enough for complex applications.

Why Learn Python?

• Simple, clean syntax that reads almost like English
• Huge standard library - "batteries included"
• Cross-platform: runs on Windows, macOS, Linux
• Massive ecosystem of third-party packages (PyPI)
• #1 language for Data Science, AI, and Machine Learning
• Strong community and excellent documentation
• Used by Google, Netflix, NASA, Instagram, and more

What Can You Build with Python?

Your First Python Program

Every Python journey starts with a simple print statement. Here's the classic "Hello, World!":

# This is a comment
print("Hello, World!")

# Variables and basic output
name = "Python"
version = 3.12
print(f"Welcome to {name} {version}!")

Python vs Other Languages

Python Versions

Python has two major version lines. Python 2 reached end-of-life in January 2020. Always use Python 3 for new projects.

Installing Python

Download Python from python.org. On Windows, check "Add Python to PATH" during installation. Verify with:

# Check Python version
python --version      # Python 3.12.x
python3 --version     # on macOS/Linux

# Run Python interactively
python

# Run a script
python hello.py

# Install packages with pip
pip install requests
pip install numpy pandas matplotlib
pip list              # show installed packages

Python Syntax Basics

Python uses indentation (whitespace) to define code blocks - no curly braces needed. This enforces clean, readable code.

# Variables - no type declaration needed
name = "Alice"
age = 25
height = 5.7
is_student = True

# Multiple assignment
x, y, z = 1, 2, 3
a = b = c = 0

# String formatting
print(f"Name: {name}, Age: {age}")          # f-string (Python 3.6+)
print("Name: {}, Age: {}".format(name, age)) # .format()

# Indentation defines blocks
if age >= 18:
    print("Adult")      # 4 spaces indent
    if age >= 65:
        print("Senior") # 8 spaces for nested block
else:
    print("Minor")

# Functions
def greet(name, greeting="Hello"):
    return f"{greeting}, {name}!"

print(greet("Bob"))           # Hello, Bob!
print(greet("Alice", "Hi"))   # Hi, Alice!

# List comprehension
squares = [x**2 for x in range(1, 6)]
print(squares)  # [1, 4, 9, 16, 25]