Unfortunately if I use .get_data I get the warning: module 'astropy.io.fits' has no attribute 'get_data' so I’m currently having to manually pull out the data using:
def __fits_loader(filename):
    file = fits.get_data(filename)
    return file

So this method is not quite working yet.
I would upload a FITS example but they are not valid extensions for this forum sorry.