tf.nest.assert_same_structure

Asserts that two structures are nested in the same way.

tf.nest.assert_same_structure(
    nest1, nest2, check_types=True, expand_composites=False
)

Note the method does not check the types of data inside the structures.

Examples:

  • These scalar vs. scalar comparisons will pass:
  tf.nest.assert_same_structure(1.5, tf.Variable(1, tf.uint32))
  tf.nest.assert_same_structure("abc", np.array([1, 2]))
  • These sequence vs. sequence comparisons will pass:
  structure1 = (((1, 2), 3), 4, (5, 6))
  structure2 = ((("foo1", "foo2"), "foo3"), "foo4", ("foo5", "foo6"))
  structure3 = [(("a", "b"), "c"), "d", ["e", "f"]]
  tf.nest.assert_same_structure(structure1, structure2)
  tf.nest.assert_same_structure(structure1, structure3, check_types=False)
    
  import collections
  tf.nest.assert_same_structure(
      collections.namedtuple("bar", "a b")(1, 2),
      collections.namedtuple("foo", "a b")(2, 3),
      check_types=False)
    
  tf.nest.assert_same_structure(
      collections.namedtuple("bar", "a b")(1, 2),
      { "a": 1, "b": 2 },
      check_types=False)
    
  tf.nest.assert_same_structure(
      { "a": 1, "b": 2, "c": 3 },
      { "c": 6, "b": 5, "a": 4 })
    
  ragged_tensor1 = tf.RaggedTensor.from_row_splits(
        values=[3, 1, 4, 1, 5, 9, 2, 6],
        row_splits=[0, 4, 4, 7, 8, 8])
  ragged_tensor2 = tf.RaggedTensor.from_row_splits(
        values=[3, 1, 4],
        row_splits=[0, 3])
  tf.nest.assert_same_structure(
        ragged_tensor1,
        ragged_tensor2,
        expand_composites=True)
  • These examples will raise exceptions:
  tf.nest.assert_same_structure([0, 1], np.array([0, 1]))
    Traceback (most recent call last):
  
    ValueError: The two structures don't have the same nested structure
    
  tf.nest.assert_same_structure(
        collections.namedtuple('bar', 'a b')(1, 2),
        collections.namedtuple('foo', 'a b')(2, 3))
    Traceback (most recent call last):
  
    TypeError: The two structures don't have the same nested structure

nest1 an arbitrarily nested structure.
nest2 an arbitrarily nested structure.
check_types if True (default) types of sequences are checked as well, including the keys of dictionaries. If set to False, for example a list and a tuple of objects will look the same if they have the same size. Note that namedtuples with identical name and fields are always considered to have the same shallow structure. Two types will also be considered the same if they are both list subtypes (which allows "list" and "_ListWrapper" from trackable dependency tracking to compare equal).
expand_composites If true, then composite tensors such as tf.sparse.SparseTensor and tf.RaggedTensor are expanded into their component tensors.

ValueError If the two structures do not have the same number of elements or if the two structures are not nested in the same way.
TypeError If the two structures differ in the type of sequence in any of their substructures. Only possible if check_types is True.