已知两条直线上各两点坐标，求两条直线交点坐标

def point(x0,y0,x1,y1,x2,y2,x3,y3):

a = y1-y0

b = x1*y0-x0*y1

c = x1-x0

d = y3-y2

e = x3*y2-x2*y3

f = x3-x2

y = float(a*e-b*d)/(a*f-c*d)

x = float(y*c-b)/a

pt = Point(x,y)

return pt