A large program can contain many functions with a wide variety of uses.
A programmer should document each function, giving a high-level description of the purpose of the function, so that later readers of the code can more easily understand.
A docstring is a string literal placed in the first line of a function body.
A docstring starts and ends with three consecutive quotation marks.
Good practice is to keep the docstring of a simple function as a single line, including the quotes. Furthermore, there should be no blank lines before or after the docstring.
Multi-line docstrings can be used for more complicated functions to describe the function arguments.
Multi-line docstrings should use consistent indentation for each line, separating the ending triple-quotes by a blank line.
The help() function can aid a programmer by providing them with all the documentation associated with an object
A statement such as help(ticket_price) would print out the docstring for the ticket_price() function, providing the programmer with information about how to call that function.