tf.data.experimental.assert_cardinality

Asserts the cardinality of the input dataset.

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tf.compat.v1.data.experimental.assert_cardinality

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.