what does this operator means in django `reduce(operator.and_, query_list)`

Question

I am reading this questions

Constructing Django filter queries dynamically with args and kwargs

I am not able to get what does this operator do

filter(reduce(operator.or_, argument_list))

or this

filter(reduce(operator.and_, query_list))

Answer 1

filter is a regular method of Django Model Manager, so there is nothing to explain.

reduce is a built-in function similar to the code below:

def reduce(func, items):
    result = items.pop()
    for item in items:
        result = func(result, item)

    return result

Where func is a user defined function.

operator.or_ is a python standard library function that wraps the or operator. It is similar to this code:

def or_(a, b):
    return a | b

For example:

reduce(operator.or_, [False, False, True])

Will return True.

In your example context, the or and the and operators are overloaded and therefore it should return a new query combined of smaller parts all concatenated by or or and operator.