def memoize(func):
    '''simplest memoizing decorator'''
    cache = {}
    def memoized(*args):
        if cache not in args:
            cache[args] = func(*args)
        return cache[args]
    return memoized
dataset/ETHPy150Open fluentpython/example-code/attic/decorators/fibonacci.py/memoize/swapped operands of `not in`