1. Single-Line Comments

Use the # symbol to write a comment on a single line.

# This is a single-line comment
x = 5  # This is an inline comment

---

2. Multi-Line Comments (Using #)

Although Python doesn’t have a built-in multi-line comment syntax, you can use # at the beginning of each line.

# This is a multi-line comment
# that spans multiple lines
# using the hash symbol.

---

3. Multi-Line Comments (Using Triple Quotes)

Triple quotes (''' or """) are often used for docstrings but can also be used as multi-line comments.

"""
This is a multi-line comment
using triple double-quotes.
"""
'''
This is another way to write
multi-line comments.
'''

Note: Triple-quoted comments are technically strings, but if not assigned to a variable, they are ignored by Python.

---

4. Docstrings (Documentation Strings)

Docstrings describe modules, functions, classes, or methods.

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

To view a function’s docstring:

print(add.__doc__)

---

5. Commenting Out Code

You can use comments to temporarily disable lines of code.

x = 10
# y = 20  # This line is ignored
print(x)

---

6. Using Comments for Debugging

You can comment out different parts of your code to isolate issues.

x = 5
# print(x + 2)
print(x * 2)  # Debugging different outputs

---

7. Best Practices for Comments

• Keep comments concise and meaningful.
• Use comments to explain why, not what.
• Avoid obvious comments.
• Use docstrings for functions, classes, and modules.
• Keep comments updated when code changes.

Example of a well-commented function:

def calculate_area(radius):
    """Returns the area of a circle given its radius."""
    pi = 3.14159  # Approximate value of π
    return pi * (radius ** 2)