fix bug in group_texts function, that was inserting short batches (#23429)

* fix bug in group_texts function, that was inserting short batches

* fully exclude short batches and return empty dict instead

* fix style

examples/pytorch/language-modeling/run_clm.py

@@ -491,9 +491,8 @@ def main():
         # Concatenate all texts.
         concatenated_examples = {k: list(chain(*examples[k])) for k in examples.keys()}
         total_length = len(concatenated_examples[list(examples.keys())[0]])
-        # We drop the small remainder, we could add padding if the model supported it instead of this drop, you can
-        # customize this part to your needs.
-        if total_length >= block_size:
+        # We drop the small remainder, and if the total_length < block_size  we exclude this batch and return an empty dict.
+        # We could add padding if the model supported it instead of this drop, you can customize this part to your needs.
         total_length = (total_length // block_size) * block_size
         # Split by chunks of max_len.
         result = {

examples/pytorch/language-modeling/run_clm_no_trainer.py

@@ -434,9 +434,8 @@ def main():
         # Concatenate all texts.
         concatenated_examples = {k: list(chain(*examples[k])) for k in examples.keys()}
         total_length = len(concatenated_examples[list(examples.keys())[0]])
-        # We drop the small remainder, we could add padding if the model supported it instead of this drop, you can
-        # customize this part to your needs.
-        if total_length >= block_size:
+        # We drop the small remainder, and if the total_length < block_size  we exclude this batch and return an empty dict.
+        # We could add padding if the model supported it instead of this drop, you can customize this part to your needs.
         total_length = (total_length // block_size) * block_size
         # Split by chunks of max_len.
         result = {

examples/pytorch/language-modeling/run_mlm.py

@@ -506,9 +506,8 @@ def main():
             # Concatenate all texts.
             concatenated_examples = {k: list(chain(*examples[k])) for k in examples.keys()}
             total_length = len(concatenated_examples[list(examples.keys())[0]])
-            # We drop the small remainder, we could add padding if the model supported it instead of this drop, you can
-            # customize this part to your needs.
-            if total_length >= max_seq_length:
+            # We drop the small remainder, and if the total_length < max_seq_length  we exclude this batch and return an empty dict.
+            # We could add padding if the model supported it instead of this drop, you can customize this part to your needs.
             total_length = (total_length // max_seq_length) * max_seq_length
             # Split by chunks of max_len.
             result = {

examples/pytorch/language-modeling/run_mlm_no_trainer.py

@@ -472,9 +472,8 @@ def main():
             # Concatenate all texts.
             concatenated_examples = {k: list(chain(*examples[k])) for k in examples.keys()}
             total_length = len(concatenated_examples[list(examples.keys())[0]])
-            # We drop the small remainder, we could add padding if the model supported it instead of this drop, you can
-            # customize this part to your needs.
-            if total_length >= max_seq_length:
+            # We drop the small remainder, and if the total_length < max_seq_length  we exclude this batch and return an empty dict.
+            # We could add padding if the model supported it instead of this drop, you can customize this part to your needs.
             total_length = (total_length // max_seq_length) * max_seq_length
             # Split by chunks of max_len.
             result = {

examples/pytorch/language-modeling/run_plm.py

@@ -450,9 +450,8 @@ def main():
             # Concatenate all texts.
             concatenated_examples = {k: list(chain(*examples[k])) for k in examples.keys()}
             total_length = len(concatenated_examples[list(examples.keys())[0]])
-            # We drop the small remainder, we could add padding if the model supported it instead of this drop, you can
-            # customize this part to your needs.
-            if total_length >= max_seq_length:
+            # We drop the small remainder, and if the total_length < max_seq_length  we exclude this batch and return an empty dict.
+            # We could add padding if the model supported it instead of this drop, you can customize this part to your needs.
             total_length = (total_length // max_seq_length) * max_seq_length
             # Split by chunks of max_len.
             result = {