Missing None verification in the CLM language modeling example

[Aunsiels]

Here:

transformers/examples/language-modeling/run_clm.py

Line 230 in 1682804

extension = data_args.train_file.split(".")[-1]

, data_args.train_file can be None (as it is checked some lines above). Therefore, there should be a check to see if it is the case or not.

[patil-suraj]

HI @Aunsiels you are right, thanks! Feel free to open PR to fix it :)

If train_file is None it should use validation_file to get the extension