How do we create multiline comments in Python?

Comments are pieces of information present in the middle of code that allows a developer to explain his work to other developers. They make the code more readable and hence easier to debug. 

Inline Comment

An inline comment is a single line comment and is on the same line as a statement. They are created by putting a ‘#’ symbol before the text.

Syntax:

# This is a single line comment

Example:

Python3

def my_fun():

    # prints Geeksforgeeks on the console
    print("GeeksforGeeks")

# function call
my_fun()

Output:

GeeksforGeeks

Note: Although not necessary, according to Python there should be a single space between # symbol and comment text and at least 2 spaces between comment and the statement.

Block Comment

Block comments in Python usually refer to the code following them and are intended to the same level as that code. Each line of block comment starts with a ‘#’ symbol.

Syntax:

# This is a block comment 
# Each line of a block comment is intended to the same level

Example:

Python3

def my_fun(i):

    # prints GFG on the console until i
    # is greater than zero dercrements i
    # by one on each iteration
    while i > 0:
        print("GFG")
        i = i-1


# calling my_fun
# it will print GFG 5 times on the console
my_fun(5)

Output:

GFG
GFG
GFG
GFG
GFG

Docstrings

The documentation string is string literal that occurs as the first statement in a module, function, class, or method definition. They explain what can be achieved by the piece of code but should not contain information about the logic behind the code. Docstrings become __doc__ special attribute of that object which makes them accessible as a runtime object attribute. They can be written in two ways:

1. One-line docstring: 

Syntax: 

"""This is a one-line docstring."""

or

'''This is one-line docstring.'''

Example:

Python3

def my_fun():
    """Greets the user."""
    print("Hello Geek!")


# function call
my_fun()

# help function on my_fun
help(my_fun)

Output: 

Hello Geek!
Help on function my_fun in module __main__:

my_fun()
    Greets the user.

Note that for one-line docstring closing quotes are on the same line as opening quotes.

2. Multi-line docstring:

Syntax:

"""This is a multi-line docstring.

The first line of a multi-line docstring consist of a summary.
It is followed by one or more elaborate description.
"""

Example:

Python3

def my_fun(user):
    """Greets the user

    Keyword arguments:
    user -- name of user
    """
    print("Hello", user+"!")

# function call
my_fun("Geek")

# help function on my_fun
help(my_fun)

Output:

Hello Geek!
Help on function my_fun in module __main__:

my_fun(user)
    Greets the user
    
    Keyword arguments:
    user -- name of user

The closing quotes must be on a line by themselves whereas opening quotes can be on the same line as the summary line. 

Some best practices for writing docstrings:

• Use triple double-quotes for the sake of consistency.
• No extra spaces before or after docstring.
• Unlike comments, it should end with a period.