python求两曲线交点

两条曲线是通过Q，t，q三组数据画出来的
Q-t与q-t
求着两线的交点咋求，求各位大佬

def line_intersection(line1, line2):
    xdiff = (line1[0][0] - line1[1][0], line2[0][0] - line2[1][0])
    ydiff = (line1[0][1] - line1[1][1], line2[0][1] - line2[1][1])
 
    def det(a, b):
        return a[0] * b[1] - a[1] * b[0]
 
    div = det(xdiff, ydiff)
    if div == 0:
       raise Exception('lines do not intersect')
 
    d = (det(*line1), det(*line2))
    x = det(d, xdiff) / div
    y = det(d, ydiff) / div
    return x, y
 
print line_intersection((A, B), (C, D))