About Python Programming Language

Think of it this way:

• Low-level: MOV AX, 5 (move the number 5 into register AX)
• High-level: x = 5 (store 5 in variable x)

Python is "high-level" because you write in almost-English commands like print(), if, and for, rather than worrying about memory addresses or processor instructions.

What Does "Interpreted" Mean?

An interpreted language runs code line-by-line through an interpreter, translating and executing each instruction on the fly—no separate compilation step needed.

Contrast:

• Compiled languages (C, C++): Write code → Compile to machine code → Run executable
• Interpreted languages (Python, JavaScript): Write code → Run directly through interpreter

Advantages of interpreted languages:

• Instant feedback (no waiting for compilation)
• Easier debugging (see errors immediately)
• Cross-platform (same code runs on Windows, Mac, Linux)

Trade-off: Interpreted languages are typically slower than compiled ones, but Python makes up for this with productivity and ease of use.

Analogy

Python is like LEGO® for software: simple blocks (syntax) that can build small scripts or giant systems depending on how you snap them together.

Visual (Mental Model)

Idea → Write readable Python → Run immediately → See result → Improve fast
  ↓           ↓                      ↓              ↓            ↓
 Goal      Code in .py           Execute      Output/Error   Iterate

Example

# hello.py
print("Hello, Python!")     # Output: Hello, Python!

What's happening here:

• # = comment (ignored by Python, helps you document code)
• print() = built-in function that displays text
• "Hello, Python!" = string (text data enclosed in quotes)

Hands-On: Getting Started with Python

Step 1: Install Python

1. Go to python.org
2. Click Downloads → Download the latest Python 3.x version (e.g., 3.10, 3.11, or newer)
3. Important during installation:
   • ✅ Check the box "Add Python to PATH" (Windows)
   • ✅ This lets you run Python from any terminal/command prompt

Step 2: Verify Installation

1. Open your terminal/command prompt:
   • Windows: Press Win + R, type cmd, hit Enter
   • Mac: Press Cmd + Space, type terminal, hit Enter
   • Linux: Press Ctrl + Alt + T
2. Type the following command and press Enter:

   python --version

   or (if the above doesn't work):

   python3 --version

3. Expected output:

   Python 3.10.5

   (Your version number may vary—that's fine as long as it's 3.x)

Step 3: Create Your First Python Script

1. Create a new folder on your Desktop (or anywhere) called python-projects
2. Open a text editor:
   • Beginner-friendly: Notepad (Windows), TextEdit (Mac), or download Visual Studio Code
   • Recommended: VS Code (it has Python support, syntax highlighting, and extensions)
3. Create a new file named hello.py inside your python-projects folder
4. Type this code:

   # hello.py
   print("Hello, Python!")

5. Save the file (important!)

Step 4: Run Your Script

1. Open your terminal/command prompt
2. Navigate to your project folder:

   cd Desktop/python-projects

   (Adjust the path based on where you created the folder)
3. Run the script:

   python hello.py

   or:

   python3 hello.py

4. Expected output:

   Hello, Python!

Common Mistakes

1. Installing Python but not adding it to PATH

Problem: You type python --version and get 'python' is not recognized as an internal or external command.

Solution:

• Re-run the Python installer
• Choose "Modify" and check "Add Python to environment variables"
• OR manually add Python to PATH (search "how to add Python to PATH [your OS]")

2. Mixing Python 2 and Python 3 tutorials

Problem: You follow an old tutorial that uses print "Hello" (Python 2) instead of print("Hello") (Python 3).

Solution:

• Always look for Python 3 tutorials (Python 2 was sunset in 2020)
• If a tutorial doesn't specify, assume it's Python 3 if it uses print() with parentheses

3. Forgetting to save the file before running

Problem: You make changes to your code, run it, but don't see the updates.

Solution:

• Always press Ctrl + S (Windows/Linux) or Cmd + S (Mac) to save before running
• Check your editor for an asterisk (*) or dot next to the filename—this indicates unsaved changes

4. Wrong file extension

Problem: Saving as hello.txt instead of hello.py.

Solution:

• Always use .py extension for Python files
• In Notepad: Choose "All Files" when saving to avoid .txt being added automatically

Mini-Project: Personal Introduction Script

Goal: Write a script that prints your name, your city, and one goal for learning Python.

Step-by-Step Instructions

Step 1: Create a new file

In your python-projects folder, create a file called intro.py

Step 2: Write the code

# intro.py - My Personal Introduction

# Store information in variables
name = "Alex"  # Replace with your name
city = "Toronto"  # Replace with your city
goal = "build a web scraper to track product prices"  # Replace with your goal

# Print introduction
print("=" * 50)  # Decorative line
print("MY PYTHON LEARNING JOURNEY")
print("=" * 50)
print()  # Empty line for spacing
print(f"👋 Hi! My name is {name}.")
print(f"📍 I'm from {city}.")
print(f"🎯 I'm learning Python to {goal}.")
print()
print("=" * 50)
print("Let's code! 🚀")
print("=" * 50)

Step 3: Customize it

• Replace "Alex", "Toronto", and the goal with your own information
• Save the file (Ctrl + S / Cmd + S)

Step 4: Run it

python intro.py

Expected Output:

==================================================
MY PYTHON LEARNING JOURNEY
==================================================

👋 Hi! My name is Alex.
📍 I'm from Toronto.
🎯 I'm learning Python to build a web scraper to track product prices.

==================================================
Let's code! 🚀
==================================================

Bonus Challenges

Once you've completed the basic version, try these:

Challenge 1: Add a question asking the user for their name

name = input("What's your name? ")
print(f"👋 Hi! My name is {name}.")

Challenge 2: Calculate how many days until your goal

days_to_goal = 90  # 90 days to learn Python
print(f"⏰ I have {days_to_goal} days to achieve my goal!")

Challenge 3: Add ASCII art (just for fun!)

print("""
  ____        _   _                 
 |  _ \ _   _| |_| |__   ___  _ __  
 | |_) | | | | __| '_ \ / _ \| '_ \ 
 |  __/| |_| | |_| | | | (_) | | | |
 |_|    \__, |\__|_| |_|\___/|_| |_|
        |___/                        
""")

Summary

Key Takeaways:

• Python is readable and powerful — You can understand code even if you've never programmed before
• Great for beginners and pros — Start with simple scripts, scale to machine learning or web applications
• You can run code instantly and iterate — No compilation wait time; see results immediately

What Makes Python Special:

1. Simple syntax — Reads like English: if user_is_happy:
2. Huge ecosystem — Libraries for everything: web (Django), data (Pandas), AI (TensorFlow), automation (Selenium)
3. Cross-platform — Write once, run on Windows, Mac, Linux
4. Strong community — Millions of developers, tons of tutorials, active forums

Your Next Steps:

1. ✅ Install Python and run your first script
2. ✅ Complete the mini-project
3. 📚 Learn variables, loops, and functions (next topics!)
4. 🚀 Build something you're excited about