Now instantiate your DataCollatorForCTCWithPadding:

data_collator = DataCollatorCTCWithPadding(processor=processor, padding="longest")

Evaluate
Including a metric during training is often helpful for evaluating your model's performance. You can quickly load a evaluation method with the 🤗 Evaluate library. For this task, load the word error rate (WER) metric (see the 🤗 Evaluate quick tour to learn more about how to load and compute a metric):

import evaluate
wer = evaluate.load("wer")