Python library for working with simple equations

[lallous]

Hello

Is there is any Python library that allow such things:

Given a string expression as: x + 5 + x * (y + 2), any library that
can develop the equation for example.
Or if we say factor with "x" then it renders the expression with x *
( rest of expression ).
There could be a functionality where when x,y are given then the
expression can be evaluated.
If there are two expressions, they can be added and the symbols
preserved.

Does such a thing exist?

Thanks,
Elias