Getting Started with Python: Complete Installation and Setup Guide 2026

# Open Command Prompt (Win + R, type cmd, press Enter)
# Verify Python installation
python --version
# Output: Python 3.14.0 (or your installed version)

# Verify pip (Python package manager) installation
pip --version
# Output: pip 24.0 from C:\Users\...\Python314\lib\site-packages\pip (python 3.14)

# Check Python installation path
where python
# Output: C:\Users\YourName\AppData\Local\Programs\Python\Python314\python.exe

# Install Homebrew (package manager for macOS)
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Follow the prompts and enter your password when requested
# After installation, run the "Next steps" commands shown
# These add Homebrew to your PATH environment variable

# Example Next steps commands (exact path may vary):
echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> ~/.zprofile
eval "$(/opt/homebrew/bin/brew shellenv)"

# Verify Homebrew installation
brew --version
# Output: Homebrew 4.2.0 (or current version)

# Install Python 3 using Homebrew
brew install python3

# Homebrew will download and install Python along with pip
# This typically takes 2-5 minutes depending on your connection

# Verify installation
python3 --version
# Output: Python 3.14.0

pip3 --version
# Output: pip 24.0 from /opt/homebrew/lib/python3.14/site-packages/pip (python 3.14)

# Check installation location
which python3
# Output: /opt/homebrew/bin/python3

# Check if Python 3 is already installed
python3 --version
# Output: Python 3.12.0 (or similar)

# If Python is not found or outdated, proceed with installation below

# Update package list
sudo apt update

# Install Python 3 and pip
sudo apt install python3 python3-pip python3-venv -y

# Install additional development tools (recommended)
sudo apt install python3-dev build-essential -y

# Verify installation
python3 --version
pip3 --version

# Check installation path
which python3
# Output: /usr/bin/python3

# For Fedora (using dnf)
sudo dnf install python3 python3-pip -y

# For RHEL/CentOS 8+ (using dnf)
sudo dnf install python3 python3-pip -y

# For older CentOS 7 (using yum)
sudo yum install python3 python3-pip -y

# Verify installation
python3 --version
pip3 --version

# Create your first Python file in VS Code
# 1. Open VS Code
# 2. Press Ctrl+N (Cmd+N on macOS) to create a new file
# 3. Save it as hello.py (Ctrl+S or Cmd+S)
# 4. Type the following code:

print("Hello, World!")
print("Welcome to Python programming!")

# 5. Run the code:
#    - Press Ctrl+F5 (Run Without Debugging)
#    - Or right-click in the editor and select "Run Python File in Terminal"
#    - Or click the play button in the top-right corner

# Output:
# Hello, World!
# Welcome to Python programming!

# First program in PyCharm
# Create a new Python file (right-click project > New > Python File)
# Name it: main.py

def greet(name):
    """Greet the user with their name."""
    return f"Hello, {name}! Welcome to Python with PyCharm."

if __name__ == "__main__":
    # Run this file by right-clicking and selecting "Run 'main'"
    # Or press Shift+F10 (Windows/Linux) or Ctrl+R (macOS)
    
    user_name = input("Enter your name: ")
    message = greet(user_name)
    print(message)
    
    print("\nPyCharm features:")
    print("- Advanced debugging with breakpoints")
    print("- Intelligent code completion")
    print("- Built-in testing support")
    print("- Integrated version control")

# Output:
# Enter your name: Alice
# Hello, Alice! Welcome to Python with PyCharm.
# 
# PyCharm features:
# - Advanced debugging with breakpoints
# - Intelligent code completion
# - Built-in testing support
# - Integrated version control

# Install Jupyter Notebook using pip (recommended method)
pip install notebook

# For Linux/macOS:
pip3 install notebook

# Alternative: Install JupyterLab (next-generation interface)
pip install jupyterlab

# Verify installation
jupyter --version
# Output: jupyter core version, notebook version, etc.

# Launch Jupyter Notebook
jupyter notebook

# This will:
# 1. Start the Jupyter server
# 2. Automatically open http://localhost:8888 in your default browser
# 3. Show the file browser where you can create new notebooks

# To stop the server: Press Ctrl+C in the terminal twice

# First Jupyter Notebook cells
# Cell 1 (Code cell): Import and greeting
import datetime

print("Hello from Jupyter Notebook!")
print(f"Current date and time: {datetime.datetime.now()}")

# Cell 2 (Code cell): Simple calculation
print("\n=== Python Calculator ===")
numbers = [1, 2, 3, 4, 5]
sum_result = sum(numbers)
average = sum_result / len(numbers)

print(f"Numbers: {numbers}")
print(f"Sum: {sum_result}")
print(f"Average: {average}")

# Cell 3 (Code cell): Data visualization example
import matplotlib.pyplot as plt

# Simple plot
x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plt.figure(figsize=(8, 4))
plt.plot(x, y, marker='o', color='blue', linewidth=2)
plt.title('My First Jupyter Plot')
plt.xlabel('X axis')
plt.ylabel('Y axis')
plt.grid(True)
plt.show()

# Note: To run each cell, click on it and press Shift+Enter
# The plot will appear directly below the cell

# Navigate to your project directory
cd my_python_project

# ===== WINDOWS =====
# Create virtual environment named 'venv'
python -m venv venv

# Activate the virtual environment
venv\Scripts\activate

# Your prompt will change to show (venv) indicating it's active


# ===== macOS / LINUX =====
# Create virtual environment
python3 -m venv venv

# Activate the virtual environment
source venv/bin/activate

# Your prompt will change to (venv) username@computer


# ===== VERIFY VIRTUAL ENVIRONMENT (All platforms) =====
# Check which Python you're using (should show path inside venv folder)
which python  # macOS/Linux
where python  # Windows

# Check Python version
python --version

# Check pip version (should also be in venv)
pip --version

# Make sure virtual environment is activated (you see (venv) in prompt)

# Install a single package
pip install requests

# Install specific version
pip install numpy==1.24.0

# Install multiple packages
pip install pandas matplotlib seaborn

# Upgrade pip itself
pip install --upgrade pip

# Upgrade a package
pip install --upgrade requests

# List installed packages
pip list

# Show details about a package
pip show requests

# Save installed packages to requirements.txt
pip freeze > requirements.txt

# Install packages from requirements.txt (for sharing projects)
pip install -r requirements.txt

# Uninstall a package
pip uninstall requests

# Deactivate virtual environment when done
deactivate

# ===== HELLO WORLD =====
# The classic first program in any language
print("Hello, World!")

# Output:
# Hello, World!


# ===== VARIABLES AND DATA TYPES =====
name = "Alice"              # String
age = 25                    # Integer
height = 5.6               # Float
is_student = True          # Boolean

print(f"Name: {name}")
print(f"Age: {age}")
print(f"Height: {height} feet")
print(f"Is student: {is_student}")

# Output:
# Name: Alice
# Age: 25
# Height: 5.6 feet
# Is student: True


# ===== USER INPUT =====
user_name = input("What is your name? ")
user_age = input("How old are you? ")

print(f"\nHello, {user_name}!")
print(f"You are {user_age} years old.")

# Interactive output:
# What is your name? Bob
# How old are you? 30
# 
# Hello, Bob!
# You are 30 years old.


# ===== BASIC ARITHMETIC =====
a = 10
b = 3

print(f"\nArithmetic Operations:")
print(f"{a} + {b} = {a + b}")      # Addition
print(f"{a} - {b} = {a - b}")      # Subtraction
print(f"{a} * {b} = {a * b}")      # Multiplication
print(f"{a} / {b} = {a / b:.2f}")  # Division
print(f"{a} // {b} = {a // b}")    # Floor division
print(f"{a} % {b} = {a % b}")      # Modulus
print(f"{a} ** {b} = {a ** b}")    # Exponentiation

# Output:
# Arithmetic Operations:
# 10 + 3 = 13
# 10 - 3 = 7
# 10 * 3 = 30
# 10 / 3 = 3.33
# 10 // 3 = 3
# 10 % 3 = 1
# 10 ** 3 = 1000

# ===== SIMPLE CALCULATOR =====
# Demonstrates functions, conditionals, and loops

def add(x, y):
    """Add two numbers."""
    return x + y

def subtract(x, y):
    """Subtract y from x."""
    return x - y

def multiply(x, y):
    """Multiply two numbers."""
    return x * y

def divide(x, y):
    """Divide x by y."""
    if y == 0:
        return "Error: Division by zero!"
    return x / y

def calculator():
    """Main calculator function."""
    print("===== Simple Calculator =====")
    print("Operations:")
    print("1. Add")
    print("2. Subtract")
    print("3. Multiply")
    print("4. Divide")
    print("5. Exit")
    
    while True:
        choice = input("\nEnter choice (1-5): ")
        
        if choice == '5':
            print("Thank you for using the calculator!")
            break
        
        if choice in ['1', '2', '3', '4']:
            try:
                num1 = float(input("Enter first number: "))
                num2 = float(input("Enter second number: "))
                
                if choice == '1':
                    print(f"Result: {num1} + {num2} = {add(num1, num2)}")
                elif choice == '2':
                    print(f"Result: {num1} - {num2} = {subtract(num1, num2)}")
                elif choice == '3':
                    print(f"Result: {num1} × {num2} = {multiply(num1, num2)}")
                elif choice == '4':
                    result = divide(num1, num2)
                    print(f"Result: {num1} ÷ {num2} = {result}")
            
            except ValueError:
                print("Invalid input! Please enter numbers only.")
        else:
            print("Invalid choice! Please select 1-5.")

# Run the calculator
if __name__ == "__main__":
    calculator()

# Example interaction:
# ===== Simple Calculator =====
# Operations:
# 1. Add
# 2. Subtract
# 3. Multiply
# 4. Divide
# 5. Exit
# 
# Enter choice (1-5): 1
# Enter first number: 15
# Enter second number: 7
# Result: 15.0 + 7.0 = 22.0
# 
# Enter choice (1-5): 5
# Thank you for using the calculator!

# ===== LISTS AND LOOPS =====
# Demonstrates Python's powerful list operations

# Create a list
fruits = ["apple", "banana", "cherry", "date", "elderberry"]

print("===== List Operations =====")
print(f"Original list: {fruits}")
print(f"First fruit: {fruits[0]}")
print(f"Last fruit: {fruits[-1]}")
print(f"Number of fruits: {len(fruits)}")

# Add items
fruits.append("fig")
print(f"\nAfter append: {fruits}")

fruits.insert(2, "coconut")
print(f"After insert at index 2: {fruits}")

# Remove items
fruits.remove("banana")
print(f"After removing banana: {fruits}")

# Loop through list
print("\nAll fruits:")
for i, fruit in enumerate(fruits, 1):
    print(f"{i}. {fruit.capitalize()}")

# List comprehension (advanced but common)
squares = [x**2 for x in range(1, 6)]
print(f"\nSquares of 1-5: {squares}")

# Filtering
long_fruits = [fruit for fruit in fruits if len(fruit) > 5]
print(f"Fruits with more than 5 letters: {long_fruits}")

# Output:
# ===== List Operations =====
# Original list: ['apple', 'banana', 'cherry', 'date', 'elderberry']
# First fruit: apple
# Last fruit: elderberry
# Number of fruits: 5
# 
# After append: ['apple', 'banana', 'cherry', 'date', 'elderberry', 'fig']
# After insert at index 2: ['apple', 'banana', 'coconut', 'cherry', 'date', 'elderberry', 'fig']
# After removing banana: ['apple', 'coconut', 'cherry', 'date', 'elderberry', 'fig']
# 
# All fruits:
# 1. Apple
# 2. Coconut
# 3. Cherry
# 4. Date
# 5. Elderberry
# 6. Fig
# 
# Squares of 1-5: [1, 4, 9, 16, 25]
# Fruits with more than 5 letters: ['coconut', 'elderberry']