STT-tensorflow/tensorflow/python/keras/saving/model_config.py
Tomer Kaftan 1b94fd1b8a Add support for creating Keras.inputs from arbitrary TypeSpecs. (Including TypeSpecs that don't have a dtype)
PiperOrigin-RevId: 350200835
Change-Id: I06772c1d6ece689f17a72d787dcd12c6f611e7e3
2021-01-05 12:58:49 -08:00

131 lines
4.4 KiB
Python

# Copyright 2018 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.
# ==============================================================================
# pylint: disable=protected-access
"""Functions that save the model's config into different formats.
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from tensorflow.python.keras.saving.saved_model import json_utils
from tensorflow.python.util.tf_export import keras_export
# pylint: disable=g-import-not-at-top
try:
import yaml
except ImportError:
yaml = None
# pylint: enable=g-import-not-at-top
@keras_export('keras.models.model_from_config')
def model_from_config(config, custom_objects=None):
"""Instantiates a Keras model from its config.
Usage:
```
# for a Functional API model
tf.keras.Model().from_config(model.get_config())
# for a Sequential model
tf.keras.Sequential().from_config(model.get_config())
```
Args:
config: Configuration dictionary.
custom_objects: Optional dictionary mapping names
(strings) to custom classes or functions to be
considered during deserialization.
Returns:
A Keras model instance (uncompiled).
Raises:
TypeError: if `config` is not a dictionary.
"""
if isinstance(config, list):
raise TypeError('`model_from_config` expects a dictionary, not a list. '
'Maybe you meant to use '
'`Sequential.from_config(config)`?')
from tensorflow.python.keras.layers import deserialize # pylint: disable=g-import-not-at-top
return deserialize(config, custom_objects=custom_objects)
@keras_export('keras.models.model_from_yaml')
def model_from_yaml(yaml_string, custom_objects=None):
"""Parses a yaml model configuration file and returns a model instance.
Usage:
>>> model = tf.keras.Sequential([
... tf.keras.layers.Dense(5, input_shape=(3,)),
... tf.keras.layers.Softmax()])
>>> try:
... import yaml
... config = model.to_yaml()
... loaded_model = tf.keras.models.model_from_yaml(config)
... except ImportError:
... pass
Args:
yaml_string: YAML string or open file encoding a model configuration.
custom_objects: Optional dictionary mapping names
(strings) to custom classes or functions to be
considered during deserialization.
Returns:
A Keras model instance (uncompiled).
Raises:
ImportError: if yaml module is not found.
"""
if yaml is None:
raise ImportError('Requires yaml module installed (`pip install pyyaml`).')
# The method unsafe_load only exists in PyYAML 5.x+, so which branch of the
# try block is covered by tests depends on the installed version of PyYAML.
try:
# PyYAML 5.x+
config = yaml.unsafe_load(yaml_string)
except AttributeError:
config = yaml.load(yaml_string)
from tensorflow.python.keras.layers import deserialize # pylint: disable=g-import-not-at-top
return deserialize(config, custom_objects=custom_objects)
@keras_export('keras.models.model_from_json')
def model_from_json(json_string, custom_objects=None):
"""Parses a JSON model configuration string and returns a model instance.
Usage:
>>> model = tf.keras.Sequential([
... tf.keras.layers.Dense(5, input_shape=(3,)),
... tf.keras.layers.Softmax()])
>>> config = model.to_json()
>>> loaded_model = tf.keras.models.model_from_json(config)
Args:
json_string: JSON string encoding a model configuration.
custom_objects: Optional dictionary mapping names
(strings) to custom classes or functions to be
considered during deserialization.
Returns:
A Keras model instance (uncompiled).
"""
config = json_utils.decode(json_string)
from tensorflow.python.keras.layers import deserialize # pylint: disable=g-import-not-at-top
return deserialize(config, custom_objects=custom_objects)