Sort a list of lists with a custom compare function

Question

I know there are several questions named like this, but they don\'t seem to work for me.

I have a list of lists, 50 times 5 elements. I want to sort this list by app

Answer 1

Also, your compare function is incorrect. It needs to return -1, 0, or 1, not a boolean as you have it. The correct compare function would be:

def compare(item1, item2):
    if fitness(item1) < fitness(item2):
        return -1
    elif fitness(item1) > fitness(item2):
        return 1
    else:
        return 0

# Calling
list.sort(key=compare)