Chapter 3. Functions

You’re already familiar with the print(), input(), and len() functions from the previous chapters. Python provides several builtin functions like these, but you can also write your own functions. A function is like a mini-program within a program.

To better understand how functions work, let’s create one. Type this program into the file editor and save it as

➊ def hello():
➋     print('Howdy!')
       print('Hello there.')
➌ hello()

The first line is a def statement ➊, which defines a function named hello(). The code in the block that follows the def statement ➋ is the body of the function. This code is executed when the function is called, not when the function is first defined.

The hello() ...

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