B
    ٻd                 @   s   d Z ddlmZ ddlmZ ddlmZ ddlmZ ddlmZ	 ddl
mZ dZd	Zed
ed eded eddd Zeddd ZG dd dejZdS )z*Cardinality analysis of `Dataset` objects.    )dataset_ops)dtypes)ops)gen_dataset_ops)gen_experimental_dataset_ops)	tf_exportz&data.experimental.INFINITE_CARDINALITYINFINITEz%data.experimental.UNKNOWN_CARDINALITYUNKNOWNzdata.experimental.cardinalityc             C   s   t | jS )a  Returns the cardinality of `dataset`, if known.

  The operation returns the cardinality of `dataset`. The operation may return
  `tf.data.experimental.INFINITE_CARDINALITY` if `dataset` contains an infinite
  number of elements or `tf.data.experimental.UNKNOWN_CARDINALITY` if the
  analysis fails to determine the number of elements in `dataset` (e.g. when the
  dataset source is a file).

  >>> dataset = tf.data.Dataset.range(42)
  >>> print(tf.data.experimental.cardinality(dataset).numpy())
  42
  >>> dataset = dataset.repeat()
  >>> cardinality = tf.data.experimental.cardinality(dataset)
  >>> print((cardinality == tf.data.experimental.INFINITE_CARDINALITY).numpy())
  True
  >>> dataset = dataset.filter(lambda x: True)
  >>> cardinality = tf.data.experimental.cardinality(dataset)
  >>> print((cardinality == tf.data.experimental.UNKNOWN_CARDINALITY).numpy())
  True

  Args:
    dataset: A `tf.data.Dataset` for which to determine cardinality.

  Returns:
    A scalar `tf.int64` `Tensor` representing the cardinality of `dataset`. If
    the cardinality is infinite or unknown, the operation returns the named
    constant `INFINITE_CARDINALITY` and `UNKNOWN_CARDINALITY` respectively.
  )r   Zdataset_cardinality_variant_tensor)dataset r   e/var/www/html/venv/lib/python3.7/site-packages/tensorflow/python/data/experimental/ops/cardinality.pycardinality!   s    r   z$data.experimental.assert_cardinalityc                s    fdd}|S )aT  Asserts the cardinality of the input dataset.

  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.
  c                s
   t |  S )N)_AssertCardinalityDataset)r   )expected_cardinalityr   r   	_apply_fn]   s    z%assert_cardinality.<locals>._apply_fnr   )r   r   r   )r   r   assert_cardinalityC   s    r   c                   s    e Zd ZdZ fddZ  ZS )r   z5A `Dataset` that assert the cardinality of its input.c                sH   || _ tj|tjdd| _tj| j j| jf| j	}t
t| || d S )Nr   )Zdtypename)Z_input_datasetr   Zconvert_to_tensorr   Zint64Z_expected_cardinalityged_opsZassert_cardinality_datasetr   Z_flat_structuresuperr   __init__)selfZinput_datasetr   Zvariant_tensor)	__class__r   r   r   f   s    z"_AssertCardinalityDataset.__init__)__name__
__module____qualname____doc__r   __classcell__r   r   )r   r   r   c   s   r   N)r   Ztensorflow.python.data.opsr   Ztensorflow.python.frameworkr   r   Ztensorflow.python.opsr   r   r   Z tensorflow.python.util.tf_exportr   r
   r   Zexport_constantr   r   r   ZUnaryUnchangedStructureDatasetr   r   r   r   r   <module>   s   " 