Python: Continuing to next iteration in outer loop

for i in ...:
    for j in ...:
        for k in ...:
            if something:
                # continue loop i

In a general case, when you have multiple levels of looping and break does not work for you (because you want to continue one of the upper loops, not the one right above the current one), you can do one of the following

Refactor the loops you want to escape from into a function

def inner():
    for j in ...:
        for k in ...:
            if something:
                return


for i in ...:
    inner()

The disadvantage is that you may need to pass to that new function some variables, which were previously in scope. You can either just pass them as parameters, make them instance variables on an object (create a new object just for this function, if it makes sense), or global variables, singletons, whatever (ehm, ehm).

Or you can define inner as a nested function and let it just capture what it needs (may be slower?)

for i in ...:
    def inner():
        for j in ...:
            for k in ...:
                if something:
                    return
    inner()

Use exceptions

Philosophically, this is what exceptions are for, breaking the program flow through the structured programming building blocks (if, for, while) when necessary.

The advantage is that you don’t have to break the single piece of code into multiple parts. This is good if it is some kind of computation that you are designing while writing it in Python. Introducing abstractions at this early point may slow you down.

Bad thing with this approach is that interpreter/compiler authors usually assume that exceptions are exceptional and optimize for them accordingly.

class ContinueI(Exception):
    pass


continue_i = ContinueI()

for i in ...:
    try:
        for j in ...:
            for k in ...:
                if something:
                    raise continue_i
    except ContinueI:
        continue

Create a special exception class for this, so that you don’t risk accidentally silencing some other exception.

Something else entirely

I am sure there are still other solutions.

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