Naming Loops in Python

Question

I recently read this question which had a solution about labeling loops in Java.

I am wondering if such a loop-naming system exists in Python. I have been in a situa

Answer 1

Here's a way to break out of multiple, nested blocks using a context manager:

import contextlib

@contextlib.contextmanager
def escapable():
    class Escape(RuntimeError): pass
    class Unblock(object):
        def escape(self):
            raise Escape()

    try:
        yield Unblock()
    except Escape:
        pass

You can use it to break out of multiple loops:

with escapable() as a:
    for i in xrange(30):
        for j in xrange(30):
            if i * j > 6:
                a.escape()

And you can even nest them:

with escapable() as a:
    for i in xrange(30):
        with escapable() as b:
            for j in xrange(30):
                if i * j == 12:
                    b.escape()  # Break partway out
                if i * j == 40:
                    a.escape()  # Break all the way out