Does anyone have an altrnate code that does the equivalent of matlab's pentropy function?

I have been looking into alternative codes that do the equivalent of the matlab function pentropy. The function calculates the spectral entropy of a signal for all times. I understand how the spectral entropy for a whole signal can be computed but I was not quite sure how it works out to determine the time dependent spectral entropy. I was wondering if someone has an alternate script that explicitly computes what the matlab function pentropy does.