Training and validation set for part one

I’m getting an error about

AttributeError: ‘NoneType’ object has no attribute ‘astype’

The above exception was the direct cause of the following exception:
My code is right here https://github.com/KeeganJustis/Fast.ai2/blob/master/courses/dl1/lesson1.ipynb
It’s a pho vs pizza classifier and I am not sure whats wrong with the data.