sir my code is not working properly…Please check it.

from fenics import *
import sympy as sym
from sympy.vector import CoordSys3D, Del
from sympy.vector import divergence
from sympy import cos, sin, pi
x, y = sym.symbols('x[0], x[1]')
R = CoordSys3D('R')
delop = Del()
mu = 1
u = (pi*cos(pi*R.y)*sin(pi*R.x)*sin(pi*R.y))*R.i + (-pi*cos(pi*R.x)*sin(pi*R.y)*sin(pi*R.x))*R.j+0*R.k
p = R.x*R.y*(1-R.x)*(1-R.y)-0.0277777
def epsilon(u):
return 0.5*(grad(u) + grad(u).T)
f1 = - 2*mu*delop.dot(epsilon(u)) + delop(p)
f = sym.simplify(f1)
u_code = sym.printing.ccode(u)
f_code = sym.printing.ccode(f)
print('u=', u_code)
print('f =', f_code)