Блог

Пожалуйста, посоветуйте, как я могу получить выходную форму или детали слоя (например, выход, output_shape) из предварительно обученной модели.

Просто найдите layer.output_shape следующие причины AttributeError: The layer has never been called and thus has no defined output shape. . Пожалуйста, помогите понять, в чем причина ошибки.

 model_name = 'distilbert-base-uncased'
max_sequence_length = MAX_SEQUENTH_LENGTH
num_labels = NUM_LABELS

from transformers import DistilBertTokenizerFast
tokenizer = DistilBertTokenizerFast.from_pretrained('distilbert-base-uncased')

def tokenize(sentences):
    return tokenizer(
        sentences,
        truncation=True,
        padding=True,
        max_length=max_sequence_length,
        return_tensors="tf"
    )
tokens = tokenize("I say hello")


from transformers import TFDistilBertModel
# Use TFDistilBertModel as TFDistilBertForSequenceClassification has classification heads added.
# base = TFDistilBertForSequenceClassification.from_pretrained(model_name, num_labels=num_labels)
base = TFDistilBertModel.from_pretrained(model_name)

# Freeze the base model weights.
for layer in base.layers:
    layer.trainable = False
base.summary()
---
Model: "tf_distil_bert_model"
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
distilbert (TFDistilBertMain multiple                  66362880  
=================================================================
Total params: 66,362,880
Trainable params: 0
Non-trainable params: 66,362,880
 

 base.compile(
    loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
    optimizer=tf.keras.optimizers.Adam(learning_rate=LEARNING_RATE),
    metrics=['accuracy']
)

for layer in base.layers:
    print(layer.output_shape)for layer in base.layers:
    print(layer.output_shape)
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-89-c8756f2a58fc> in <module>()
      1 for layer in base.layers:
----> 2     print(layer.output_shape)

/usr/local/lib/python3.7/dist-packages/tensorflow/python/keras/engine/base_layer.py in output_shape(self)
   2136     """
   2137     if not self._inbound_nodes:
-> 2138       raise AttributeError('The layer has never been called '
   2139                            'and thus has no defined output shape.')
   2140     all_output_shapes = set(

AttributeError: The layer has never been called and thus has no defined output shape.
 

Обходной путь

 base_model_output = base(tokens)
base_model_output.last_hidden_state.shape
---
TensorShape([2, 6, 768])