while loop

A while loop repeats as long as its condition is true.

i = 1
while i <= 5:
    print(i)
    i = i + 1      # without this line the loop never ends!
print("Done")

This prints 1 to 5, then Done.

i += 1 is a short way to write i = i + 1. The same works for -=, *= and so on.

If the condition never becomes false, you get an infinite loop. Here, the code is stopped after 5 seconds, so don't worry about breaking anything.