def euclidean_distance(x0, y0, x1=0.0, y1=0.0, squared=False):
    """EUCLIDEAN DISTANCE

    Euclidean distance between (x0, y0) and (x1, y1)
    """
    d_squared = (x1 - x0) ** 2 + (y1 - y0) ** 2
    if squared:
        return d_squared
    else:
        return d_squared ** 0.5
