Computing derivative after using replace method

[VisualCoder123]

Good evening!

I'm currently replacing sympy with SymEngine in my project. It's speed is amazing! Unfortunately, there are a few lines of code that I currently don't know how to convert for SymEngine.

The code evaluates large amount of derivatives. With sympy, I don't evaluate them in place, but using doit() method to get the final expression.

Unfortunately I didn't found any similar method in SymEngine. Maybe I'm missing something?

Source code demonstrating the problem:

from symengine import *
x, y = symbols('x y')
f = Function('f')(x, y)

expr = diff(f, x)
expr2 = expr.replace(f, x*y)# Derivative(x*y, x) 

How to evaluate expr2?

Using simplify at this expression evaluates the derivative. But I'm interested in something like doit() which just evaluates all the unevaluated objects. As I understand, simplify makes some additional optimization which I don't need because the real expression contains several hundreds of terms. Could you suggest a possible solution to this issue?

With best regards,
Yuri