from functools import reduce
from functools import reduce
def add(x, y):
  return x + y
print(reduce(add, [1, 2, 3, 4, 5])) #计算过程 ((((1 + 2) + 3) + 4) + 5)
# 运行结果
15

from functools import reduce
print(reduce(lambda x, y: x + y, [1, 2, 3, 4, 5]))
# 运行结果
15

from functools import reduce

print(reduce(lambda x, y: x + y, [1, 2, 3, 4, 5], 6))

# 运行结果
21

#计算过程
6 + 1 = 7
7 + 2 = 9
9 + 3 = 12
12 + 4 = 16
16+ 5 = 21