Ah, sorry! Completely forgot. You get this if you have a record that can't find a spans
.
Change to this (I've also updated the code above):
for eg in examples:
if eg.get('spans') is not None:
for span in eg.get('spans'):
span['text'] = eg['text'][span['start']:span['end']]
By using eg.get('spans')
instead of eg["spans"]
you won't get an error when it doesn't find a key.
Crossing fingers that this should work