Python Entry 11th Day _ function

Python functions

Functions are well-organized, reusable pieces of code that are used to implement a single, or associated function.

Unlike a function definition in mathematics, a function can be called a subroutine in a computer.

Functions can improve the modularity of the application, and the reuse of the code. You already know that Python provides a number of built-in functions, such as print (). But you can also create your own functions, which are called user-defined functions.

Define a function

You can define a function that you want to function, and here are the simple rules:

• The function code block begins with a def keyword followed by the function identifier name and parentheses ().
• Any incoming parameters and arguments must be placed in the middle of the parentheses. Parentheses can be used to define parameters.
• The first line of the function statement can optionally use the document string-for storing the function description.
• The function contents begin with a colon and are indented.
• return [expression] ends the function, optionally returning a value to the caller. Return without an expression is equivalent to returning None.

Syntax of the function

def functionname (Parameters):    " Function _ Document string "    function_suite   return [expression]

By default, parameter values and parameter names are matched in the order defined in the function declaration.

Python Entry 11th Day _ function