docstring.py

def square(n):
    '''Takes in a number n, returns the square of n'''
    print(n**2)
square(5)

def add(num1, num2):
    """
    Add up two integer numbers.

    This function simply wraps the ``+`` operator, and does not
    do anything interesting, except for illustrating what
    the docstring of a very simple function looks like.

    Parameters
    ----------
    num1 : int
        First number to add.
    num2 : int
        Second number to add.

    Returns
    -------
    int
        The sum of ``num1`` and ``num2``.

    See Also
    --------
    subtract : Subtract one integer from another.

    Examples
    --------
    add(2, 2)
    4
    add(25, 0)
    25
    add(10, -10)
    0
    """
    return num1 + num2

def square(n):
    '''Takes in a number n, returns the square of n'''
    return n**2

print(square.__doc__) # it is used to print the description of function encloed in triple single quotation mark.