Discussion on: Advanced Python: for more attractive code

The 'else' is used if the loop completes successfully, so if the loop ends early, such as by using a 'break' statement, the 'else' won't run. It's just an easier way to run code if and only if the loop finishes successfully without needing to use a flag variable to detect whether the loop finishes.

With flag:

flag = True
for i in range(10):
    if i == 8:
        flag = False
if flag:
    print('Loop completed') # won't print, since flag is False

With 'else':

for i in range(10):
    if i == 8:
        break
else:
    print('Loop completed') # won't print since the loop ended early

In both cases, the text won't print, since the loop didn't complete. However, if the loops did complete, then the text would print.