[M2M100Tokenizer] fix _build_translation_inputs (#14382)

* add return_tensors paramter

* fix test

* Apply suggestions from code review
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* style
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/models/m2m_100/tokenization_m2m_100.py

@@ -332,7 +332,7 @@ class M2M100Tokenizer(PreTrainedTokenizer):
         if src_lang is None or tgt_lang is None:
             raise ValueError("Translation requires a `src_lang` and a `tgt_lang` for this model")
         self.src_lang = src_lang
-        inputs = self(raw_inputs, add_special_tokens=True, return_tensors="pt", **extra_kwargs)
+        inputs = self(raw_inputs, add_special_tokens=True, **extra_kwargs)
         tgt_lang_id = self.get_lang_id(tgt_lang)
         inputs["forced_bos_token_id"] = tgt_lang_id
         return inputs

tests/test_tokenization_m2m_100.py

@@ -226,7 +226,7 @@ class M2M100TokenizerIntegrationTest(unittest.TestCase):
 
     @require_torch
     def test_tokenizer_translation(self):
-        inputs = self.tokenizer._build_translation_inputs("A test", src_lang="en", tgt_lang="ar")
+        inputs = self.tokenizer._build_translation_inputs("A test", return_tensors="pt", src_lang="en", tgt_lang="ar")
 
         self.assertEqual(
             nested_simplify(inputs),