Comments are annotations used to help others understand your code. They don't affect how a program is run.

In Python, a comment can be created by inserting an "#", also known as a number sign or hash symbol. The text after it on a line will be ignored.

Unlike other programming languages, Python doesn't have a syntax for multiline comments, so you will need consecutive single-line comments if you want to express more than one idea.

Here's an example:

x = 7
y = 5

def simple_sum(x, y): #custom function called simple_sum
    print(x + y) #printing simple_sum 

simple_sum(x, y) #final result

Docstrings (documentation strings) are similar to comments, except that they have a different syntax and are retained throughout the runtime of a program. This is useful for the programmer to inspect key comments during run time.

Also, docstrings can contain multiple lines of text.

You can create docstrings by adding a multiline string containing an explanation below a function's first line, as follows:

s = input()

def hashtagGen(text):
    """
    This program will replace spaces between a random text, 
    adding a '#' symbol to generate a hashtag. 
    """
    ht = s.replace(" ", "")

    return "#" + ht

print(hashtagGen(s))