xref: /aosp_15_r20/external/tensorflow/tensorflow/python/summary/summary_iterator.py (revision b6fb3261f9314811a0f4371741dbb8839866f948)
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 tensorflow.core.util import event_pb2
19from tensorflow.python.lib.io import tf_record
20from tensorflow.python.util.tf_export import tf_export
21
22
23class _SummaryIterator(object):
24  """Yields `Event` protocol buffers from a given path."""
25
26  def __init__(self, path):
27    self._tf_record_iterator = tf_record.tf_record_iterator(path)
28
29  def __iter__(self):
30    return self
31
32  def __next__(self):
33    r = next(self._tf_record_iterator)
34    return event_pb2.Event.FromString(r)
35
36  next = __next__
37
38
39@tf_export(v1=['train.summary_iterator'])
40def summary_iterator(path):
41  # pylint: disable=line-too-long
42  """Returns a iterator for reading `Event` protocol buffers from an event file.
43
44  You can use this function to read events written to an event file. It returns
45  a Python iterator that yields `Event` protocol buffers.
46
47  Example: Print the contents of an events file.
48
49  ```python
50  for e in tf.compat.v1.train.summary_iterator(path to events file):
51      print(e)
52  ```
53
54  Example: Print selected summary values.
55
56  ```python
57  # This example supposes that the events file contains summaries with a
58  # summary value tag 'loss'.  These could have been added by calling
59  # `add_summary()`, passing the output of a scalar summary op created with
60  # with: `tf.compat.v1.summary.scalar('loss', loss_tensor)`.
61  for e in tf.compat.v1.train.summary_iterator(path to events file):
62      for v in e.summary.value:
63          if v.tag == 'loss':
64              print(tf.make_ndarray(v.tensor))
65  ```
66  Example: Continuously check for new summary values.
67
68  ```python
69  summaries = tf.compat.v1.train.summary_iterator(path to events file)
70  while True:
71    for e in summaries:
72        for v in e.summary.value:
73            if v.tag == 'loss':
74                print(tf.make_ndarray(v.tensor))
75    # Wait for a bit before checking the file for any new events
76    time.sleep(wait time)
77  ```
78
79  See the protocol buffer definitions of
80  [Event](https://www.tensorflow.org/code/tensorflow/core/util/event.proto)
81  and
82  [Summary](https://www.tensorflow.org/code/tensorflow/core/framework/summary.proto)
83  for more information about their attributes.
84
85  Args:
86    path: The path to an event file created by a `SummaryWriter`.
87
88  Returns:
89    A iterator that yields `Event` protocol buffers
90  """
91  return _SummaryIterator(path)
92