Prove Euler's theorem with Sympy

Question

I am trying to use Sympy for this problem, however I'm having some trouble with the code. Here's what I have so far. The error message is that "g is not a callable function".

from sympy import *

x, y, z, λ, m = symbols('x y z λ m',real=True)

g = Function('g')(x,y,z)

LHS = g(λ*x,λ*y,z)

RHS = (λ**m)*g(x,y,z)

expr = Eq(LHS,RHS)

display(expr)