a = [1,5,6,9,10,11,12,13,15,18] def max_value(a,b): return a if a > b else b def max_sequence(x): result = x[0] for element in x: result = max_value(result, element) return result print(max_sequence(a)) def min_value(a,b): return b if a > b else a def min_sequence(x): result = x[0] for element in x: result = min_value(result, element) return result print(min_sequence(a)) def reduce1(fn,x): result = x[0] for element in x: result = fn(result, element) return result def reduce2(fn,x,init): result = init for element in x: result = fn(result, element) return result def sum1(a,b): return a + b print(reduce1(max_value, a)) print(reduce1(min_value, a)) print(reduce2(sum1, a, 0)) print(reduce2(max_value, a, a[0])) print("=================") from functools import reduce print(reduce(sum1,a,0))