Python equivalent of 'clamp(cubic(),min,max)' in a parm?

[danvenn 0]

Hi, 
I'm playing around with limiting transform handles on nulls to act as a rigging control surface.
I found on these forums a cool hscript snippet that allows this: clamp(cubic(),min,max).
Does anyone know the python equivalent? The python clamp doesn't seem to accept a cubic() as a parameter.

Also, does anyone know of another method of allowing for manual transform handle input that feeds into an expression? (HScript or Python).
I can't wrap my head around why cubic() works!

 

Cheers
Dan