Does Gensim handling pad index and UNK index in W2V models?
A Gensim Word2Vec model only learns, and reports, vectors for words that it learned during training.
If you want it to learn some vector for any synthetic 'unknown' or 'padding' symbols, you need to include them in the training data. (They may not be very interesting/useful vector-values, though, and having such synthetic token vectors may not outperform simply ignoring unknown-tokens or avoiding artificial padding entirely.)
I'm using Gensim for building W2V models and, I didn't find a way for adding a vector for Unkown words or padding parts in Gensim and, I have to do it manually.
I also check the index of 0 in the created embedding and, it is also used for a specific word. This matter could cause a problem for padding words because they have the same index.
Am I missing something in here? Is Gensim handle this problem?
P.S: For handling this issue, I always append two vectors in the model weights after I train the model.