Find the token count of each document/row.

tokens is either a RaggedTensor or SparseTensor, representing tokenized strings. This function simply returns size of each row, so the dtype is not constrained to string.

tokens either (1) a two-dimensional SparseTensor, or (2) a RaggedTensor with ragged rank of 1, non-ragged rank of 1 of dtype tf.string containing tokens to be counted
name (Optional) A name for this operation.

A one-dimensional Tensor the token counts of each row.

ValueError if tokens is neither sparse nor ragged