It works like built-in split(). Hint: message you're writing about is Expected an error when empty delimiter!, that means that there is delimeter, but just empty..

na, you have to throw an error/exception if you don't get a delimiter.

Tho, that is when the delimiter is actually empty. when it's "somehting else", you have to do... something else... :/

I'm a bit confused by the "No delimeter should throw an error" test. Even some dummy test code using the .split() function doesn't throw an error in python 3.6 (see below). Using raise ValueError just stops the whole thread.

    if not delimiter:
        return string.split()
        
    return string.split(delimiter)
    

You can do a simple test: execute a single for loop on the lists and watch your code time out.

1. Use markdown to display code.
2. Solution needs to use O(n) time. It looks like you have a for loop in a for loop, which if I'm not mistaken is o(n^2^2). Very slow.

If you do a print call on ints you can see the output of the final tests are in excess of 10mB. Solution needs to use O(n) time.

I have to disagree: given that the error returned is "[9, 10, 0] should equal [1, 0, 0, 0]" It seems fairly clear that the input is [9,10,0], which appears to be invalid per the rule "Input must be a single digit, non-negative int"