1# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14# ==============================================================================
15
16"""Provides a method for reading events from an event file via an iterator."""
17
18from __future__ import absolute_import
19from __future__ import division
20from __future__ import print_function
21
22from tensorflow.core.util import event_pb2
23from tensorflow.python.lib.io import tf_record
24from tensorflow.python.util.tf_export import tf_export
25
26
27@tf_export(v1=['train.summary_iterator'])
28def summary_iterator(path):
29  # pylint: disable=line-too-long
30  """An iterator for reading `Event` protocol buffers from an event file.
31
32  You can use this function to read events written to an event file. It returns
33  a Python iterator that yields `Event` protocol buffers.
34
35  Example: Print the contents of an events file.
36
37  ```python
38  for e in tf.train.summary_iterator(path to events file):
39      print(e)
40  ```
41
42  Example: Print selected summary values.
43
44  ```python
45  # This example supposes that the events file contains summaries with a
46  # summary value tag 'loss'.  These could have been added by calling
47  # `add_summary()`, passing the output of a scalar summary op created with
48  # with: `tf.summary.scalar('loss', loss_tensor)`.
49  for e in tf.train.summary_iterator(path to events file):
50      for v in e.summary.value:
51          if v.tag == 'loss':
52              print(v.simple_value)
53  ```
54
55  See the protocol buffer definitions of
56  [Event](https://www.tensorflow.org/code/tensorflow/core/util/event.proto)
57  and
58  [Summary](https://www.tensorflow.org/code/tensorflow/core/framework/summary.proto)
59  for more information about their attributes.
60
61  Args:
62    path: The path to an event file created by a `SummaryWriter`.
63
64  Yields:
65    `Event` protocol buffers.
66  """
67  # pylint: enable=line-too-long
68  for r in tf_record.tf_record_iterator(path):
69    yield event_pb2.Event.FromString(r)
70