MobileNetV2 is still one of the most efficient architectures for image classification. Considering that TensorFlow 2.0 has already hit version beta1, I think that a flexible and reusable implementation of MobileNetV2 in TF 2.0 might be useful for practitioners.
Implementation
I implemented a running mean and standard deviation calculation with Welford algorithm, which eliminates the problem of loading the whole dataset into the memory. Normalizer class, calculating the mean and standard deviation, is also used as a preprocessing_function argument to tf.keras.preprocessing.image.ImageDataGenerator.