description: Asserts the cardinality of the input dataset.

tf.data.experimental.assert_cardinality

Asserts the cardinality of the input dataset.

tf.data.experimental.assert_cardinality(
    expected_cardinality
)

NOTE: The following assumes that "examples.tfrecord" contains 42 records.

>>> dataset = tf.data.TFRecordDataset("examples.tfrecord")
>>> cardinality = tf.data.experimental.cardinality(dataset)
>>> print((cardinality == tf.data.experimental.UNKNOWN_CARDINALITY).numpy())
True
>>> dataset = dataset.apply(tf.data.experimental.assert_cardinality(42))
>>> print(tf.data.experimental.cardinality(dataset).numpy())
42

Args

expected_cardinality The expected cardinality of the input dataset.

Returns

A Dataset transformation function, which can be passed to tf.data.Dataset.apply.

Raises

FailedPreconditionError The assertion is checked at runtime (when iterating the dataset) and an error is raised if the actual and expected cardinality differ.