Breaking out of nested loops

Possible Duplicate:
How to break out of multiple loops in Python?

Is there an easier way to break out of nested loops than throwing an exception? (In Perl, you can give labels to each loop and at least continue an outer loop.)

for x in range(10):
    for y in range(10):
        print x*y
        if x*y > 50:
            "break both loops"

Ie, is there a nicer way than:

class BreakIt(Exception): pass

try:
    for x in range(10):
        for y in range(10):
            print x*y
            if x*y > 50:
                raise BreakIt
except BreakIt:
    pass

---

It has at least been suggested, but also rejected. I don't think there is another way, short of repeating the test or re-organizing the code. It is sometimes a bit annoying.

In the rejection message, Mr van Rossum mentions using return , which is really sensible and something I need to remember personally. :)

---

for x in xrange(10):
    for y in xrange(10):
        print x*y
        if x*y > 50:
            break
    else:
        continue  # only executed if the inner loop did NOT break
    break  # only executed if the inner loop DID break

对于更深层次的循环也是一样：

for x in xrange(10):
    for y in xrange(10):
        for z in xrange(10):
            print x,y,z
            if x*y*z == 30:
                break
        else:
            continue
        break
    else:
        continue
    break

---

If you're able to extract the loop code into a function, a return statement can be used to exit the outermost loop at any time.

def foo():
    for x in range(10):
        for y in range(10):
            print x*y
            if x*y > 50:
                return
foo()

If it's hard to extract that function you could use an inner function, as @bjd2385 suggests, eg

def your_outer_func():
    ...
    def inner_func():
        for x in range(10):
            for y in range(10):
                print x*y
                if x*y > 50:
                    return
    inner_func()
    ...

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