Breaking out of Nested For Loops (Python)

# Break out of a nested for loop when 'emma' is reached
# Python does not have a goto statement to do this!
# Tested with Python24     vegaseat     12sep2006

# create a list of lists ...
list1 = [['frank', 'joe', 'mary'], ['carl', 'emma', 'jerry'], ['harry', 'matt', 'sue']]

# you can set a flag ...
done = False
for list2 in list1:
    if done:
        break
    for item in list2:
        print item
        if item == 'emma':
            done = True
            # this break only breaks out of this inner loop
            # needs the 'if done' to carry it out of all loops
            break

print

# or raise an exception ...
try:
    for list2 in list1:
        for item in list2:
            print item
            if item == 'emma':
                # raise an exception
                raise StopIteration()
except StopIteration:
    pass

print

# or use a function and force a return ...
def break_nestedloop(list1):
    for list2 in list1:
        for item in list2:
            print item
            if item == 'emma':
                # force a return
                return

dummy = break_nestedloop(list1)  # returns None