tf.strings.unsorted_segment_join

Joins the elements of inputs based on segment_ids.

tf.strings.unsorted_segment_join(
    inputs, segment_ids, num_segments, separator='', name=None
)

Computes the string join along segments of a tensor.

Given segment_ids with rank N and data with rank N+M:

output[i, k1...kM] = strings.join([data[j1...jN, k1...kM])

where the join is over all [j1...jN] such that segment_ids[j1...jN] = i.

Strings are joined in row-major order.

For example:

inputs = ['this', 'a', 'test', 'is']
segment_ids = [0, 1, 1, 0]
num_segments = 2
separator = ' '
tf.strings.unsorted_segment_join(inputs, segment_ids, num_segments,
                                 separator).numpy()
array([b'this is', b'a test'], dtype=object)
 
inputs = [['Y', 'q', 'c'], ['Y', '6', '6'], ['p', 'G', 'a']]
segment_ids = [1, 0, 1]
num_segments = 2
tf.strings.unsorted_segment_join(inputs, segment_ids, num_segments,
                                 separator=':').numpy()
array([[b'Y', b'6', b'6'],
       [b'Y:p', b'q:G', b'c:a']], dtype=object)

inputs A list of tf.Tensor objects of type tf.string.
segment_ids A tensor whose shape is a prefix of inputs.shape and whose type must be tf.int32 or tf.int64. Negative segment ids are not supported.
num_segments A scalar of type tf.int32 or tf.int64. Must be non-negative and larger than any segment id.
separator The separator to use when joining. Defaults to "".
name A name for the operation (optional).

A tf.string tensor representing the concatenated values, using the given separator.