Where 'data' is a list, the first element being the initial balance, the second element being a list of withdrawals (plural... despite the fact that it's called 'withdrawal' when it's unpacked).
Why bother with the list unpacking?
Why not just define the function as:
def checkio(balance, widthdrawals):
pass
EDIT: Giving it some thought, I assume future problems will use the same 'checkio' function, so it has to have the same argument list...
Using kwargs might be more Pythonic, if that's a design constraint...
