def sum(iterable, start=None): """NGSolve sum function that uses the first element of an iterable as start argument if no start argument is provided.""" if start is not None: return builtin_sum(iterable, start) generator = iter(iterable) try: first = next(generator) except StopIteration: return 0 return builtin_sum(generator, first)
def sum(x): return builtin_sum(x)