What's the feature "item_gender" in DIN / DIEN?

[Curlykonda]

Describe the question(问题描述) What does the feature column with the name item_gender represent? Is it an indication of click/not-clicked corresponding to the item at that position?

If so, why do we have a vocabulary size of 2+1? Why should we record items in the history that were not clicked?

Additional context In the example run-files run_din.py and run_dien.py the sparse features hist_item_gender are added to the feature columns together with hist_item.

Operating environment(运行环境):

• deepctr version [e.g. 0.7.1,]

[shenweichen]

item_gender means which gender(male or female) will prefer this item more.2+1,2 is for male and female,1 is for missing value