Is it possible to simplify expressions using the sympy library, for example sqrt (x^2) = abs (x)?

Question

I reviewed the sympy documentation and did not find such a thing. Using the simplify method, sqrt(x**2) does not change.

Answer 1

I presume you are hoping that sqrt(x**2) will simplify to x. The problem is that this is not a valid simplification in general e.g.:

In [23]: z = -1

In [24]: z**2
Out[24]: 1

In [25]: sqrt(z**2)
Out[25]: 1

In [26]: sqrt(z**2) == z
Out[26]: False

When declaring a symbol you can set assumptions that are needed for simplification like this to be possible:

In [27]: x = Symbol('x', real=True)

In [28]: y = Symbol('y', positive=True)

In [29]: sqrt(x**2)
Out[29]: │x│

In [30]: sqrt(y**2)
Out[30]: y