Trainer (#3800)

* doc

* [tests] Add sample files for a regression task

* [HUGE] Trainer

* Feedback from @sshleifer

* Feedback from @thomwolf + logging tweak

* [file_utils] when downloading concurrently, get_from_cache will use the cached file for subsequent processes

* [glue] Use default max_seq_length of 128 like before

* [glue] move DataTrainingArguments around

* [ner] Change interface of InputExample, and align run_{tf,pl}

* Re-align the pl scripts a little bit

* ner

* [ner] Add integration test

* Fix language_modeling with API tweak

* [ci] Tweak loss target

* Don't break console output

* amp.initialize: model must be on right device before

* [multiple-choice] update for Trainer

* Re-align to 827d6d6ef0

src/transformers/configuration_utils.py

@@ -87,7 +87,7 @@ class PretrainedConfig(object):
         self.architectures = kwargs.pop("architectures", None)
         self.finetuning_task = kwargs.pop("finetuning_task", None)
         self.num_labels = kwargs.pop("num_labels", 2)
-        self.id2label = kwargs.pop("id2label", {i: "LABEL_{}".format(i) for i in range(self.num_labels)})
+        self.id2label = kwargs.pop("id2label", {i: f"LABEL_{i}" for i in range(self.num_labels)})
         self.id2label = dict((int(key), value) for key, value in self.id2label.items())
         self.label2id = kwargs.pop("label2id", dict(zip(self.id2label.values(), self.id2label.keys())))
         self.label2id = dict((key, int(value)) for key, value in self.label2id.items())