如何修复使用 sympy 符号表达式引起的类型错误

如何解决如何修复使用 sympy 符号表达式引起的类型错误

我正在根据许多符号表示创建一个变量：

m,R,e,rho,V,C_L,c,Omega,psi,q_dot,p_dot,q,p=sym.symbols('m,p')
I_e = 1/3 * m *(R-e)**3
S_e = 1/2 * m * (R-e) **3
M_A = (rho*V**2*C_L*c*(R**2-e**2))/4

M_beta = (1/(I_e*Omega**2))*(M_A+(I_e+e*S_e)*Omega**2*(q_dot/Omega)*sym.cos*(psi)-\
                            (I_e+e*S_e)*Omega**2*(p_dot/Omega)*sym.sin(psi)-\
                             2*(I_e+e*S_e)*Omega**2*(q/Omega)*sym.sin(psi)-\
                             2*(I_e+e*S_e)*Omega**2*(p/Omega)*sym.cos(psi))

然而，这个错误发生了，我不知道如何解决：

TypeError                                 Traceback (most recent call last)
<ipython-input-29-86d345ec5696> in <module>
      6 M_beta = (1/(I_e*Omega**2))*(M_A+(I_e+e*S_e)*Omega**2*(q_dot/Omega)*sym.cos*(psi)-\
      7                             (I_e+e*S_e)*Omega**2*(p_dot/Omega)*sym.sin(psi)-\
----> 8                              2*(I_e+e*S_e)*Omega**2*(q/Omega)*sym.sin(psi)-\
      9                              2*(I_e+e*S_e)*Omega**2*(p/Omega)*sym.cos(psi))
     10 

~\Anaconda3\lib\site-packages\sympy\core\decorators.py in __sympifyit_wrapper(a,b)
     89                 if not hasattr(b,'_op_priority'):
     90                     b = sympify(b,strict=True)
---> 91                 return func(a,b)
     92             except SympifyError:
     93                 return retval

~\Anaconda3\lib\site-packages\sympy\core\decorators.py in binary_op_wrapper(self,other)
    127                     if f is not None:
    128                         return f(self)
--> 129             return func(self,other)
    130         return binary_op_wrapper
    131     return priority_decorator

~\Anaconda3\lib\site-packages\sympy\core\expr.py in __mul__(self,other)
    194     @call_highest_priority('__rmul__')
    195     def __mul__(self,other):
--> 196         return Mul(self,other)
    197 
    198     @_sympifyit('other',NotImplemented)

~\Anaconda3\lib\site-packages\sympy\core\operations.py in __new__(cls,*args,**options)
     45             return args[0]
     46 
---> 47         c_part,nc_part,order_symbols = cls.flatten(args)
     48         is_commutative = not nc_part
     49         obj = cls._from_args(c_part + nc_part,is_commutative)

~\Anaconda3\lib\site-packages\sympy\core\mul.py in flatten(cls,seq)
    305                 #      e
    306                 # o = b
--> 307                 b,e = o.as_base_exp()
    308 
    309                 #  y

TypeError: as_base_exp() missing 1 required positional argument: 'self'

我一遍又一遍地检查我的代码，但仍然不知道如何解决这个问题。有人可以给我一个提示吗？