如何修正变量中的无效语法

Question

无效的语法不断出现在ap，r_ddot或ddy上。

def odeFunc（t，R）：

    r2=(R[[0]]**2+R[[1]]**2+R[[2]]**2)(0.5)

#Constants
    mu=3.98716708E5 #gravitational parameters [km^3/s^2]
    Re=6378.137 #Radius of earth
    J= 0.0010826267
    gamma= (5*R[2]**2)/(r2**2) #Partial coeff used to calculate ap
    lambd= (-3*J*mu*Re**2)/(2*r2**5)

 #Pertubation due to non-spherical earth
    ap = np.reshape(np.array([[lambd*R[0]*(1-gamma)],[lambd*R[1]*(1-gamma)],[lambd*R[2]*(3-gamma)]],(3,1)

    r_ddot = (-mu*R[0:3])/(r2**3) + ap #acceleration

    ddy = [np.zeros((6,1))]

    ddy = np.reshape(np.array([[R[3]],[R[4]],[R[5]],[r_ddot[0]],[r_ddot[1]],[r_ddot[2]],(6,1) #return value of acc and vel

    return ddy