how to see if there is a value in a list that is between two values from another list

I have two lists

a = [1, 4, 12]
b = [2, 13]

I want to know if values in list b are between two values in list a So, in this case, 2 will fall between 1 and 4. 13 will not fall between any numbers.

I have tried bisect function, but I couldn't get it work. I was able to use it with a single value and a list, but not two lists.

Solution

It really depends on what you want it to return. I wrote a code that will return the first pattern that it finds, but with some changes I'm sure it would not be difficult to return all combinations.

def get_between(a, b):
    a, b = sorted(a), sorted(b)
    
    for b_value in b:
        smaller = None
        greater = None
        for a_value in a:
            if b_value > a_value:
                smaller = a_value
            elif b_value < a_value:
                greater = a_value
            
            if smaller and greater:
                return f"{b_value} is between {smaller} and {greater}"
    
    return "There is no such combination"

a = [1, 4, 12]
b = [2, 13]
print(get_between(a, b))

The output on that case will be 2 is between 1 and 4, but you can adapt the return value to be whatever you want.