def distance_between(agents_row_a, agents_row_b):
    """
    This function calculates and returns the distance between two sets of 
    points on the x, y plane.

    Parameters
    ----------
    agents_row_a : an object of the Agent class
        A object representing an agent, which includes x and y variables of
        the agent's position on a 2D plane.
    agents_row_b : an object of the Agent class
        A object representing an agent, which includes x and y variables of
        the agent's position on a 2D plane.

    Returns
    -------
    Float
        Returns the calculated Pythagorean distance between two agent objects
        which include their coords on the x, y plane.

    """
    return (((agents_row_a.x - agents_row_b.x)**2) + \
            ((agents_row_a.y - agents_row_b.y)**2))**0.5