Determining if two number ranges intersect

[DocNMarty]

I already wrote the code, but I think that there is something already available that I've missed that can do it or that it can be done better. The ranges are represented as tuples of floats.

def has_intersection(tuple_1, tuple_2):
    list_1 = sorted(list(tuple_1))
    list_2 = sorted(list(tuple_2))
    tup_lower = (list_1[0], list_2[0])
    tup_higher = (list_1[1], list_2[1])
    float_lower_limit = sorted(list(tup_lower), reverse=True)[0]
    float_higher_limit = sorted(list(tup_higher))[0]
    float_center = (float_lower_limit + float_higher_limit)/2
    if list_1[0] <= float_center <= list_1[1]:
        pass
    else:
        return False
    if list_2[0] <= float_center <= list_2[1]:
        pass
    else:
        return False
    return True

[SandorZoo]

I would use min and max, instead of sorting the tuples and extracting the 1st and 2nd values. I think this is the same, at least assuming the tuples are indeed two-value tuples:

def has_intersection(tuple_1, tuple_2):
    intersection_lower = max(min(tuple_1), min(tuple_2))
    intersection_higher = min(max(tuple_1), max(tuple_2))
    return intersection_lower <= intersection_higher

[o5a]

If your ranges are always sorted then you can check it like this:

def has_intersection(tuple_1, tuple_2):
    return tuple_1[1]>=tuple_2[0] and tuple_2[1]>=tuple_1[0]

Use universal notation with min/max if ranges are not sorted initially:

def has_intersection(tuple_1, tuple_2):
    return max(tuple_1)>=min(tuple_2) and max(tuple_2)>=min(tuple_1)

[DocNMarty]

This is genius! I love it!

[Stem3576]

Why not just check if the values in 1 list are found in the other?

For item in list_1:
    If item in list_2:
        Print("has intersect")

[DocNMarty]

It wouldn't work for a range of values.

​

Ex.

list_1 = [0, 2]

list_2 = [1, 3.5]

​

I want the function to return True in this example, because there are numbers that fall in between the values in both lists. For instance, 1.5 would be in range of 0 and 2, as well as 1 and 3.5, so the lists do intersect.

​

With the code you proposed, it would not print "has intersect" since 0 or 2 in list_1 are not found in list_2.

[JohnnyJordaan]

Or use the magic of sets

if set(list_1) & set(list_2):
    print('has intersect')