有没有一种在SymPy中使用球面坐标的方法？

import sympy as sp
from sympy.vector import CoordSys3D
from sympy.vector.vector import cross
from sympy.vector.vector import dot
from sympy.vector.vector import gradient
from sympy.vector.vector import divergence
from sympy.vector.vector import curl

N = CoordSys3D('N')
r, theta, phi = sp.symbols('r theta phi')
spherical_coords = (r, theta, phi)
P = N.locate_new('P', r * sp.sin(theta) * sp.cos(phi) * N.i + r * sp.sin(theta) * sp.sin(phi) * N.j + r * sp.cos(theta) * N.k)

# 球面坐标到直角坐标的转换
rectangular_coords = P.express_coordinates(N)

# 直角坐标到球面坐标的转换
spherical_coords = N.to_spherical(rectangular_coords)

# 计算球面坐标的梯度、散度和旋度
grad = gradient(f, spherical_coords)
div = divergence(v, spherical_coords)
curl = curl(v, spherical_coords)