Computes overlap between two ranges

compute_overlap.py

import numpy as np

def compute_overlap(x1, x2, y1, y2):
    if x2 >= y1 and y2 >= x1:
        if x1 < y1 < x2 and x2 < y2:
            return x2 - y1
        elif y1 < x1 < y2 and y2 < x2:
            return y2 - x1
        elif x1 < y1 and y2 < x2:
            return y2 - y1
        elif y1 < x1 and x2 < y2:
            return x2 - x1
    else:
        return np.nan