ordering tensorflow validation and test set

In Tensorflow for Retrain Inception for New Categories, there is option for "--testing_percentage" and "--validation_percentage".

Is there a way to order the images for testing and validation? For example I have 100 images (50 images in dogs categories and 50 images in cats categories); I order files in two directories in numered filenames (01dog.jpg, 02dog.jpg .... 50dog.jpg in a folder; 01cat.jpg, 02cat.jpg .... 50cat.jpg in a different folder). After I use 10% for testing_percentage and 10% for validation_percentage.

I would like that tensorflow uses files:

• from 01dog.jpg to 40dog.jpg for training,
• files from 41dog.jpg to 45dog.jpg for validation and
• files from 46dog.jpg to 50dog.jpg for testing.

There is a way? I try to order files in this ways, but tensorflow does not follow the order.

In "http://ift.tt/2gnLIZ9": "Note that the script uses the image filenames (rather than a completely random function) to divide the images among the training, validation, and test sets. This is done to ensure that images don't get moved between training and testing sets on different runs, since that could be a problem if images that had been used for training a model were subsequently used in a validation set."

Thanks and regards