coefficient(L, D)
This function returns the coefficient of $D$ along the prime divisor generated by $L$ assuming $L$ is the ordered list of an element
i1 : R = QQ[x,y,u,v]/ideal(x*y-u*v);
i2 : E = divisor(x*u) o2 = Div(v, x) + Div(u, y) + 2*Div(u, x) o2 : WeilDivisor on R
i3 : coefficient({u, x}, E) o3 = 2
i4 : coefficient({x, u}, E) o4 = 0