import math


def point_distance(point_a, point_b):
    """ Calculate distance between to points.

    Args:
        point_a (list(float)): coordinate of the first point, [x, y]
        point_b (list(float)): coordinate of the second point, [x, y]

    Returns:
        float: distance between the two points.
    """
    return math.sqrt((point_b[0] - point_a[0]) ** 2 + (point_b[1] - point_a[1]) ** 2)