Pchip Algorithm

Hello, I want to use PiecewiseCubicHermiteSplineInterpolator class in my code to interpolate values. Basically I need the function and interpolated values as scipy.interpolate.PchipInterpolator in python(https://docs.scipy.org/doc/scipy/reference/generated/scipy.interpolate.PchipInterpolator.html). In this library, I am not clear how to get the interpolated values and the function?
It is not clear why it returns a 2D array of coefficients?