python: exit out of two loops

This one uses a boolean to see if you are done yet:

done = False
for x in xs:
    for y in ys:
        if bad:
            done = True
            break

    if done:
        break

This one will continue if no break was used. The else will be skipped over if there was a break, so it will see the next break. This approach has the benefit of not having to use a variable, but may be harder to read to some.

for x in xs:
    for y in ys:
        if bad:
            break
    else:
        continue

    break