UnimplementedError: Cast string to float is not supported..我该如何解决这种错误，请

Question

当我运行以下代码时，出现此类型错误：

<块引用>

（未实现错误：不支持将字符串转换为浮点数 [[节点顺序_5/Cast（定义于：11）]] [操作：__inference_train_function_4357] 函数调用栈： train_function)

我使用的是 Anaconda（jupyter notebook），python 3.8.5。如何解决这个问题？

    import tensorflow as tf
    from tensorflow import keras
    from sklearn.metrics import confusion_matrix , classification_report
    def ANN(X_train, y_train, X_test, y_test, loss, weights):
        model = keras.Sequential([
            keras.layers.Dense(1, input_dim=1, activation='relu'),
            keras.layers.Dense(15, activation='relu'),
            keras.layers.Dense(1, activation='sigmoid')
        ])
    
        model.compile(optimizer='adam', loss=loss, metrics=['accuracy'])
        
        if weights == -1:
            model.fit(X_train, y_train, epochs=100)
        else:
            model.fit(X_train, y_train, epochs=100, class_weight = weights)
        
        print(model.evaluate(X_test, y_test))
        
        y_preds = model.predict(X_test)
        y_preds = np.round(y_preds)
        
        print("Classification Report: \n", classification_report(y_test, y_preds))
        
        return y_preds
    loss = keras.losses.BinaryCrossentropy()
    weights = -1
    y_preds = ANN(X_train, y_train, X_test, y_test, 'binary_crossentropy', -1)