python - keras.metrics 没有属性 'Metric'

Question

我尝试使用 Keras Tuner 进行超参数优化:

import keras
from kerastuner import HyperModel
from kerastuner.tuners import Hyperband

input_shape = (1, 28, 28)
num_classes = 10

# Define hypermodel class
class CNNHyperModel(HyperModel):
    def __init__(self, input_shape, num_classes):
        self.input_shape = input_shape
        self.num_classes = num_classes

    def build(self, hp):
        model = Sequential()
        model.add(Conv2D(32, kernel_size=(3, 3), activation="relu", input_shape=input_shape))
        model.add(Conv2D(64, (3, 3), activation="relu"))
        model.add(MaxPooling2D(pool_size=(2, 2)))
        model.add(Dropout(0.25))
        model.add(Flatten())
        model.add(Dense(128, activation="relu"))
        model.add(Dropout(0.5))
        model.add(Dense(num_classes, activation="softmax"))

        model.compile(
            loss=keras.losses.categorical_crossentropy,
            optimizer=keras.optimizers.Adadelta(),
            metrics=["accuracy"],
        )

        return model

# Instantiate
hypermodel = CNNHyperModel(input_shape=input_shape, num_classes=num_classes)

# Create tuner
HYPERBAND_MAX_EPOCHS = 40
MAX_TRIALS = 20
EXECUTION_PER_TRIAL = 2
SEED = 1

tuner = RandomSearch(
    hypermodel,
    max_epochs=HYPERBAND_MAX_EPOCHS,
    objective='val_accuracy',
    seed=SEED,
    max_trials=MAX_TRIALS,
    executions_per_trial=EXECUTION_PER_TRIAL,
    directory='hyperband',
    project_name='mnist'
)

我明白了

AttributeError: module 'tensorflow._api.v1.keras.metrics' has no attribute 'Metric'

使用 conda 安装了 Tensorflow 1.13 和 2.0。

按照 this answer 中的建议，包括 from tensorflow.python.keras.metrics import Metric不会改变任何东西。

Answer 1

最新版本的 Tensorflow 2.6.0 有 tf.keras.metrics.Metric API。

您可以导入为

from tensorflow.keras.metrics import Metric