Getting Started With Raspberry Pi, 4th Edition

Use functions to put chunks of code into a code block that can

be called from other places in your script. To rewrite the previous

example with functions, do the following (when you go to run this

sketch, save it as

CountEvens.py

):

# Declare global variables

n=0

# Setup function

def setup():

global n

n = 100

def loop():

global n

n = n + 1

if ((n % 2) == 0):

print(n)

# Main

setup()

while True:

loop()

In this example, the output will be every even number from 102 on.

Here’s how it works:

First, the variable n is defined as a global variable that can be

used in any block in the script.

Here, the setup() function is defined (but not ...