How reduce function work with operators in python?-CodePudding

I already import this

from functools import reduce

import operator

when i try this


>>> print(reduce(operator.or_, \[2,4,5]))

7

>>> print(reduce(operator.or_, \[2,4,6]))

6

>>> print(reduce(operator.or_, \[2,3,6]))

7

>>> print(reduce(operator.or_, \[2,3,8]))

8

I'm pretty confused, i dont know how does exactly it work ?

CodePudding user response：

Reduce applies the bitwise OR operator to each successive pair of elements in the input array. For example in your first case, it starts with 2 and 4. Bitwise OR on 2 (010 in binary) and 4 (100) gives 6 (110). The bitwise OR is then applied to 6 i.e. result of computation and 5 (101) i.e. the next element in the array, resulting in 7 (111). Similarly for the rest.

CodePudding user response：

operator.or_ is a bitwise operation, so

reduce(operator.or_, [2,4,5])

2 | 4 | 5

which is

2 = 010
4 = 100
5 = 101
-------
7 = 111

Unfortunately, there's no equivalent of or in operator module, so:

>>> reduce(lambda a, b: a or b, [2,4,5])
2