[]:classify_pde(eq)[]:('1st_linear_constant_coeff_homogeneous',)function this way:from sympy import Function, Derivativefrom sympy.abc import x, y # x and y are the independent variablesf =Function("f")(x, y)# f is a function of x and y#fx will be the partial derivative of f with respect to xfx =Derivative(f, x)#fy will be the partial derivative of f with respect to yfy =Derivative(f, y)