'Inverse' cumprod in pandas
Just in case anyone else ends up here, let me provide a more generic answer.
Suppose your DataFrame column, Series, vector, whatever, X has n values. At an arbitrary position i you'd like to get 
(X[i])*(X[i+1])*...*(X[n]), 
which is equivalent to 
(X[1])*(X[2])*...*(X[n]) / (X[1])*(X[2])*...*(X[i-1]). 
Therefore, you may just do
inverse_cumprod = (np.prod(X) / np.cumprod(X)) * X
I have a data frame which contains dates as index and a value column storing growth percentage between consecutive dates (i.e. dates in the index). Suppose I want to compute 'real' values by setting a 100 basis at the first date of the index and then iteratively applying the % of growth. It is easy with the cumprod method.
Now, I want to set as 100 basis the laste date in the index. I thus need to compute for each date in the index the 'inverse' growth. Is there an easy way (and pythonic) to do this with pandas?
Regards,
Allia