“‘Model”对象没有属性“loss_functions”

Question

我已经完成了NLP的udacity纳米学位。我在项目中使用了udacity平台，但现在我正在尝试使用自己的本地机器来训练模型等。

我终于解决了我的GPU/tensorflow问题(我想)，但我遇到了一些问题，我相信这些问题与udacity使用的tensorflow版本有关。

我当前使用的是TensorFlow 2.2

具体地说，我从项目用来列出损失函数的验证步骤中得到一个错误。

def _test_model(model, input_shape, output_sequence_length, french_vocab_size):
    if isinstance(model, Sequential):
        model = model.model
        
    print(model.loss_functions)

当它被调用时，我得到“‘模型’对象没有属性'loss_functions'”错误。

该模型是使用以下代码构建的。

def simple_model(input_shape, output_sequence_length, english_vocab_size, french_vocab_size):
    """
    Build and train a basic RNN on x and y
    :param input_shape: Tuple of input shape
    :param output_sequence_length: Length of output sequence
    :param english_vocab_size: Number of unique English words in the dataset
    :param french_vocab_size: Number of unique French words in the dataset
    :return: Keras model built, but not trained
    """
   
    # TODO: Build the layers
    
    learning_rate = 0.01
    
    #Config Model
    inputs = Input(shape=input_shape[1:])
    hidden_layer = GRU(output_sequence_length, return_sequences=True)(inputs)
    outputs = TimeDistributed(Dense(french_vocab_size, activation='softmax'))(hidden_layer)
    
    #Create Model from parameters defined above
    model = keras.Model(inputs=inputs, outputs=outputs)
    #loss_function = 'sparse_categorical_crossentropy'
    loss_fn = keras.losses.SparseCategoricalCrossentropy()
    model.compile(loss=loss_fn,optimizer=Adam(learning_rate),metrics=['accuracy'])

在此过程中，我使用了下面的库

import tensorflow as tf
from tensorflow.keras.losses import sparse_categorical_crossentropy
from tensorflow.keras.optimizers import Adam
from tensorflow import keras
import collections


import helper
import numpy as np
import project_tests as tests

from tensorflow.keras.preprocessing.text import Tokenizer
from tensorflow.keras.preprocessing.sequence import pad_sequences
from tensorflow.keras.models import Model, Sequential

from tensorflow.keras.layers import GRU, Input, Dense, TimeDistributed, Activation, RepeatVector, Bidirectional, Dropout
from tensorflow.keras.layers.embeddings import Embedding
from tensorflow.keras.optimizers import Adam
from tensorflow.keras.losses import sparse_categorical_crossentropy

我可以注释掉损失函数的检查，但我真的很想了解发生了什么。

谢谢

Answer 1

我认为Tensorflow 2中的API改变了，做了以下工作：

model.compiled_loss._get_loss_object(model.compiled_loss._losses).fn