# Copyright 2015 The TensorFlow Authors. All Rights Reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# ==============================================================================

"""Provides a method for reading events from an event file via an iterator."""

from __future__ import absolute_import

from __future__ import division

from __future__ import print_function

from tensorflow.core.util import event_pb2

from tensorflow.python.lib.io import tf_record

from tensorflow.python.util.tf_export import tf_export

@tf_export(v1=['train.summary_iterator'])

def summary_iterator(path):

# pylint: disable=line-too-long

"""An iterator for reading `Event` protocol buffers from an event file.

You can use this function to read events written to an event file. It returns

a Python iterator that yields `Event` protocol buffers.

Example: Print the contents of an events file.

```python

for e in tf.train.summary_iterator(path to events file):

print(e)

```

Example: Print selected summary values.

```python

# This example supposes that the events file contains summaries with a

# summary value tag 'loss'. These could have been added by calling

# `add_summary()`, passing the output of a scalar summary op created with

# with: `tf.summary.scalar('loss', loss_tensor)`.

for e in tf.train.summary_iterator(path to events file):

for v in e.summary.value:

if v.tag == 'loss':

print(v.simple_value)

```

See the protocol buffer definitions of

[Event](https://www.tensorflow.org/code/tensorflow/core/util/event.proto)

and

[Summary](https://www.tensorflow.org/code/tensorflow/core/framework/summary.proto)

for more information about their attributes.

Args:

path: The path to an event file created by a `SummaryWriter`.

Yields:

`Event` protocol buffers.

"""

# pylint: enable=line-too-long

for r in tf_record.tf_record_iterator(path):

yield event_pb2.Event.FromString(r)