How can I invert y = pow(x, z) to get x?

Question

As I know there is no build-in functions to do this directly, so log()? or a simple math shortcut like:

z = y ** (1/x)

x?

Answer 1

If y=pow(x,z) then x = pow(y,1.0/z):

>>> y = pow(3,1.7)
>>> y
6.473007839923779
>>> pow(y,1.0/1.7)
3.0