Python Comments

What Are Comments?

In programming, comments are lines of text added to code for explanations or clarifications. They are ignored by the compiler or interpreter, making them purely for human understanding. Comments improve code readability and aid in understanding by documenting complex algorithms or providing context for future readers or maintainers.

Python Comments Syntax

In Python, comments start with the hash symbol (#). Anything written after the hash is ignored by the interpreter. For example:

# This is a comment in Python


Benefits of Using Comments

1. Enhance Readability: Comments make it easier for others to understand the logic behind the code.
2. Code Explanation: Programmers can describe what a specific block or line of code does.
3. Aid in Code Reuse: Detailed explanations help other programmers use existing code without deciphering its functionality.
4. Reminders: Serve as annotations for the original author to revisit and improve their code.

Types of Comments in Python

Single-line Comments

A single-line comment starts with a hash symbol (#) and is used for short explanations or annotations to a single line of code. Example:

‍


# This line calculates the sum of two numbers
result = num1 + num2

Multi-line Comments

Multi-line comments, also known as block comments, span multiple lines. They are enclosed between triple quotes (""" or '''). Example:

"""
This function calculates the average of a list of numbers.
First, it sums all the numbers in the list.
Then, it divides the sum by the number of elements.
Finally, it returns the calculated average.
"""
def calculate_average(numbers_list):
    pass

Docstring Comments

Docstring comments provide documentation for functions, modules, or classes. They are enclosed between triple quotes and are used by tools like automated documentation generators. Example:

def calculate_factorial(n):
    """
    This function calculates the factorial of a given number.
    It takes an integer as input and returns the factorial.
    """
    pass

Single-line Comments

Definition and Usage

Single-line comments are denoted by the hash symbol (#) and are used to add explanatory notes or disable specific lines of code. They enhance code readability and manage the execution of code during development. Example:

# Assigning the value 5 to the variable 'x'
x = 5

Examples

Variable Explanation:

# Assigning the value 5 to the variable 'x'
x = 5

Function Declaration:

# This function adds two numbers and returns the result
def add_numbers(a, b):    
		return a + b

Expression Explanation:

# Calculating the sum of the list elements
sum = 0
for num in list:    
		sum += num

Multi-line Comments

Usage

To create multi-line comments, you can use either single-line comments for each line or multiline strings enclosed within triple quotes. Multiline strings are preferred for their simplicity and readability. Example:

"""
This is a multi-line comment.
It can span multiple lines.
"""

Documentation Strings

Docstrings describe the functionality of functions, classes, modules, and methods. They come in two types:

One-liner Docstrings: A brief description on the same line as the declaration.

def add(a, b):
    """Adds two numbers."""
    return a + b

Multi-line Docstrings: Detailed descriptions spanning multiple lines.

def add(a, b):
    """
    Adds two numbers and returns the result.

    Parameters:
    a (int): The first number.
    b (int): The second number.

    Returns:
    int: The sum of the two numbers.
    """
    return a + b

By using docstrings, developers can provide clear and informative explanations, contributing to well-documented and understandable code.