data issue

[dinhthangbkhn]

data = pd.merge(data, pd.DataFrame({self.item_key:itemids, 'ItemIdx':self.itemidmap[itemids].values}), on=self.item_key, how='inner')
After merged with pd.DataFrame({self.item_key:itemids, 'ItemIdx':self.itemidmap[itemids].values}), the data 's order is based on itemidx order. So I think the code for processing data after is not true.

[Songweiping]

Data is sorted by session key and time key (in init function) again just below the line you mentioned.