Function not changing global variable

Your issue is that functions create their own namespace, which means that done within the function is a different one than done in the second example. Use global done to use the first done instead of creating a new one.

def function():
    global done
    for loop:
        code
        if not comply:
            done = True

An explanation of how to use global can be found here

Use global, only then you can modify a global variable otherwise a statement like done = True inside the function will declare a new local variable named done:

done = False
def function():
    global done
    for loop:
        code
        if not comply:
            done = True

Read more about the global statement.

done=False
def function():
    global done
    for loop:
        code
        if not comply:
            done = True

you need to use the global keyword to let the interpreter know that you refer to the global variable done, otherwise it's going to create a different one who can only be read in the function.