【TensorFlow】ValueError: 'validation_split' is only supported for Tensors or NumPy arrays
算例：『Analyzing Models with TensorBoard - Deep Learning with Python, TensorFlow and Keras p.4 - YouTube』
⚠ 执行 model.fit(X, y, batch_size=32, epochs=3, validation_split=0.3, callbacks=[tensorboard]) 时报错：
解决方法参考该答案，将 y 转换为 numpy array 即可。
