Lists and loops: averaging sensor readings

A list holds many values in order: readings = [10, 20, 30]. A for loop visits each one:

total = 0
for r in readings:
    total = total + r
print(total)        # 60
print(len(readings)) # 3, how many items

Good programs handle the awkward cases too. What should happen when the list is empty?

Your turn

Write average(readings) that returns the average of a list of numbers. For an empty list, return 0 instead of crashing.

Your code

Press Run to see what your code prints.