💬 Python Comments — Writing Cleaner, Understandable Code

Introduction 🌟

Comments are notes you write inside your code for yourself or other developers. Python ignores comments while running the program, meaning they don’t affect the output.

Note

💡 Comments make code easier to understand, maintain, and debug.

1. What Are Comments? 🤔

Comments are used to explain what the code does. They are extremely helpful when revisiting your code after weeks or when working in teams.

basic_comment.py

# This is a comment
print("Hello Python!")  # This prints a message

2. Single-Line Comments (#) ✍️

The # symbol starts a comment. Everything after it on that line is ignored.

single_line_comment.py

# This is a single-line comment
x = 10  # Inline comment
print(x)

Note

💡 Use single-line comments to explain a specific line or quick idea.

3. Multi-Line Comments (""" """) 📚

Python doesn't have true multi-line comment syntax, but developers use triple-quoted strings to create block comments.

multi_line_comment.py

"""
This is a multi-line comment.
You can write explanations here.
Python ignores this as long as it is not assigned to a variable.
"""
print("Learning Python Comments!")

Note

🧠 Triple quotes are also used for docstrings — special comments for functions & classes.

4. Inline Comments 📝

Inline comments appear on the same line as code — useful for short explanations.

inline_comment.py

speed = 80  # speed in km/h
print(speed)

5. Docstrings (Documentation Strings) 📘

Docstrings describe functions, classes, and modules. These are written using triple quotes inside the definition and can be accessed with help().

docstring_example.py

def add(a, b):
    """This function adds two numbers and returns the result."""
    return a + b

print(add(10, 20))
help(add)

Note

✨ Docstrings are displayed in IDEs, documentation tools, and Python's help system.

6. Why Use Comments? 🎯

  • Explain complex logic
  • Make code readable for teammates
  • Help future you understand old code
  • Describe function usage (via docstrings)

7. When NOT to Use Comments 🚫

Comments should not replace clean code. Avoid:

  • Writing comments for obvious lines (e.g., x = 5 # set x to 5)
  • Using long paragraphs — keep comments short and meaningful
  • Outdated or incorrect comments — they cause confusion

Note

🧼 Best practice: Write self-explanatory code and use comments only where needed.

8. Real-World Example 🧪

real_world_example.py

# Ask user for their name
name = input("Enter your name: ")

# Greet the user
print(f"Hello, {name}!")

def calculate_discount(price):
    """
    This function calculates a 10% discount
    and returns the final amount.
    """
    return price - (price * 0.1)

print(calculate_discount(100))

Conclusion 🎉

>>“Good code is understood by computers. Great code is understood by humans.” ✨

You now know how to use comments to make your Python code clean and professional. Want the next lesson on Operators, Expressions, Conditional Statements, Loops, or Functions? Just tell me! 😊