add relevant description to tqdm in examples (#11927)

* add relevant `desc` in examples

* require_version datasets>=1.8.0

examples/pytorch/text-classification/run_glue.py

@@ -42,10 +42,12 @@ from transformers import (
 )
 from transformers.trainer_utils import get_last_checkpoint
 from transformers.utils import check_min_version
+from transformers.utils.versions import require_version
 
 
 # Will error if the minimal version of Transformers is not installed. Remove at your own risks.
 check_min_version("4.7.0.dev0")
+require_version("datasets>=1.8.0", "To fix: pip install -r examples/pytorch/text-classification/requirements.txt")
 
 task_to_keys = {
     "cola": ("sentence", None),
@@ -393,7 +395,12 @@ def main():
             result["label"] = [(label_to_id[l] if l != -1 else -1) for l in examples["label"]]
         return result
 
-    datasets = datasets.map(preprocess_function, batched=True, load_from_cache_file=not data_args.overwrite_cache)
+    datasets = datasets.map(
+        preprocess_function,
+        batched=True,
+        load_from_cache_file=not data_args.overwrite_cache,
+        desc="Running tokenizer on dataset",
+    )
     if training_args.do_train:
         if "train" not in datasets:
             raise ValueError("--do_train requires a train dataset")