问如何使用SymPy集成指定特定的虚拟变量

EN

import numpy as np
import seaborn
import math
import pandas as pd
import matplotlib as plt
import scipy.integrate as integrate
import scipy.special as special
from sympy import init_session

init_session()
%matplotlib inline

dP, dT = symbols('dP dT', real = True, positive = True)
dr = symbols('dr', real = True, positive = True)
T_9, T = symbols('T_9 T', real = True, positive = True)
rho, mu, m_u, k, P, gamma = symbols('rho mu m_u k P gamma', real = True, positive = True)
r, R_solar, R = symbols('r R_solar R', real = True, positive = True)
G, M_solar, M = symbols('G M_solar M', real = True, positive = True)
a, c, kappa = symbols('a c kappa', real = True, positive = True)
F = symbols('F', real = True, positive = True)

cc = (T / (rho * k * T / (mu * m_u)) * (1 - (1 / gamma)) * ((-rho * G * M / r**2)))

r_int = integrate(((cc), (0, r, R)))