reduce and opeator

Reduce is operation that reducing an array into a single value.
For example multiplying all element in the array
a=[1,2,3,4,5,6]
​
from functools import reduce
from operator import mul
a=[1,2,3]
​
reduce(mul, a)
# 6
​
# or with lambda
​
reduce(lambda x, y: x*y, a)
# 6