I understand that the Holt-Winters' seasonal multiplicative method needs the data to have non-zero values. Accordingly, functions such as
statsmodels.tsa.holtwinters.ExponentialSmoothing do not allow for the use of multiplicative seasonality (or trend) if the data contains zeros - or even negative values.
But many seasonal time series do contain zeros, and I would expect it to be possible to use the same methods maybe with some trick to make it work.
In my particular case, I added 0.01 to all entries of my dataset, and then the algorithm ran well with decent results. But it seems fishy.
Is this what one should do, or is it something else?