Whether an axis is inverted can now be queried and set using the .axes.Axes getters ~.Axes.get_xinverted/~.Axes.get_yinverted and setters ~.Axes.set_xinverted/~.Axes.set_yinverted.
The previously existing methods (.Axes.xaxis_inverted, .Axes.invert_xaxis) are now discouraged (but not deprecated) due to their non-standard naming and behavior.