1# Copyright 2018 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# pylint: disable=protected-access 16"""Functions that save the model's config into different formats.""" 17 18from tensorflow.python.keras.saving.saved_model import json_utils 19from tensorflow.python.util.tf_export import keras_export 20 21 22@keras_export('keras.models.model_from_config') 23def model_from_config(config, custom_objects=None): 24 """Instantiates a Keras model from its config. 25 26 Usage: 27 ``` 28 # for a Functional API model 29 tf.keras.Model().from_config(model.get_config()) 30 31 # for a Sequential model 32 tf.keras.Sequential().from_config(model.get_config()) 33 ``` 34 35 Args: 36 config: Configuration dictionary. 37 custom_objects: Optional dictionary mapping names 38 (strings) to custom classes or functions to be 39 considered during deserialization. 40 41 Returns: 42 A Keras model instance (uncompiled). 43 44 Raises: 45 TypeError: if `config` is not a dictionary. 46 """ 47 if isinstance(config, list): 48 raise TypeError('`model_from_config` expects a dictionary, not a list. ' 49 'Maybe you meant to use ' 50 '`Sequential.from_config(config)`?') 51 from tensorflow.python.keras.layers import deserialize # pylint: disable=g-import-not-at-top 52 return deserialize(config, custom_objects=custom_objects) 53 54 55@keras_export('keras.models.model_from_yaml') 56def model_from_yaml(yaml_string, custom_objects=None): 57 """Parses a yaml model configuration file and returns a model instance. 58 59 Note: Since TF 2.6, this method is no longer supported and will raise a 60 RuntimeError. 61 62 Args: 63 yaml_string: YAML string or open file encoding a model configuration. 64 custom_objects: Optional dictionary mapping names 65 (strings) to custom classes or functions to be 66 considered during deserialization. 67 68 Returns: 69 A Keras model instance (uncompiled). 70 71 Raises: 72 RuntimeError: announces that the method poses a security risk 73 """ 74 raise RuntimeError( 75 'Method `model_from_yaml()` has been removed due to security risk of ' 76 'arbitrary code execution. Please use `Model.to_json()` and ' 77 '`model_from_json()` instead.' 78 ) 79 80 81@keras_export('keras.models.model_from_json') 82def model_from_json(json_string, custom_objects=None): 83 """Parses a JSON model configuration string and returns a model instance. 84 85 Usage: 86 87 >>> model = tf.keras.Sequential([ 88 ... tf.keras.layers.Dense(5, input_shape=(3,)), 89 ... tf.keras.layers.Softmax()]) 90 >>> config = model.to_json() 91 >>> loaded_model = tf.keras.models.model_from_json(config) 92 93 Args: 94 json_string: JSON string encoding a model configuration. 95 custom_objects: Optional dictionary mapping names 96 (strings) to custom classes or functions to be 97 considered during deserialization. 98 99 Returns: 100 A Keras model instance (uncompiled). 101 """ 102 config = json_utils.decode(json_string) 103 from tensorflow.python.keras.layers import deserialize # pylint: disable=g-import-not-at-top 104 return deserialize(config, custom_objects=custom_objects) 105