Manipulating an sympy expression with .func() and args

Question

I have this expression: $expr = \frac{2 A B}{A m + m} + C^2 + D^2$

and I want to get: $expr = \frac{2 B}{m \left( 1 + \frac{1}{A} \right)} + C^2 + D^2$

I am trying to use expr.args to get the term that interests me, but I fail to get out the A and the m in the denominator. I have the impression to be stock on a vicious circle. In the documentation, I see that expr.func() could be a way to do it. But it evades me.

Any suggestions? Thank you in advance How should I write latex expression?

Answer 1

>>> from sympy import *
>>> from sympy.abc import A, B, C, D, m
>>> expr = 2*A*B/(A*m + m) + C**2 + D**2
>>> i, d = expr.as_independent(C,D);1/factor_terms(expand(1/i))+d
2*B/(m*(1 + 1/A)) + C**2 + D**2