Range Continued

The range() function we've been using in our for loops actually has an optional 3rd parameter: the "step".

for i in range(0, 10, 2):
    print(i)
# prints:
# 0
# 2
# 4
# 6
# 8

The "step" parameter determines how much to add to i in each iteration of the loop. You can even go backwards:

for i in range(3, 0, -1):
    print(i)
# prints:
# 3
# 2
# 1

Assignment

Fix the for loop in the count_down function. It takes start and end inputs, but start is always greater than end. It's supposed to print numbers counting down from start to end, exclusive, but there's a mistake in the range function call.

Tip

In the programming world, it's common for the first number in a range to be inclusive and the second number is exclusive. e.g. range(0, 10) will include:

0 1 2 3 4 5 6 7 8 9

def count_down(start, end):

for i in range(start, end):

print(i)

# Don't edit below this line

def test(start, end):

print(f"Using inputs start: {start} and end: {end}")

print(f"Printing numbers from {start} to {end + 1}:")

count_down(start, end)

print("=====================================")

def main():

test(10, 0)

test(20, 10)

test(15, 11)

main()