"""
user=> (transduce (map inc) + 0 [1 2 3])
9
user=> (transduce (map inc) - 10 [1 2 3])
-1

"""

def transduce(transducer, reducer, iterable, memo):
    return reduce(transducer(reducer), iterable, memo)


def transducer(fn):
    def wrapper(a, b):
        return fn(a, b) + 1
    return wrapper

def reducer(acc, n):
    return acc + n

print(transduce(transducer, reducer, [1, 2, 3], 0))