Tokenizers should be framework agnostic (#8599)

* Tokenizers should be framework agnostic

* Run the slow tests

* Not testing

* Fix documentation

* Apply suggestions from code review
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

.github/workflows/self-push.yml

@@ -16,7 +16,7 @@ on:
 
 jobs:
   run_tests_torch_gpu:
-    runs-on: [self-hosted, single-gpu]
+    runs-on: [self-hosted, gpu, single-gpu]
     steps:
       - uses: actions/checkout@v2
       - name: Python version
@@ -86,7 +86,7 @@ jobs:
                   
 
   run_tests_tf_gpu:
-    runs-on: [self-hosted, single-gpu]
+    runs-on: [self-hosted, gpu, single-gpu]
     steps:
       - uses: actions/checkout@v2
       - name: Python version
@@ -154,7 +154,7 @@ jobs:
           path: reports
 
   run_tests_torch_multi_gpu:
-    runs-on: [self-hosted, multi-gpu]
+    runs-on: [self-hosted, gpu, multi-gpu]
     steps:
       - uses: actions/checkout@v2
       - name: Python version
@@ -213,7 +213,7 @@ jobs:
           path: reports
 
   run_tests_tf_multi_gpu:
-    runs-on: [self-hosted, multi-gpu]
+    runs-on: [self-hosted, gpu, multi-gpu]
     steps:
       - uses: actions/checkout@v2
       - name: Python version

.github/workflows/self-scheduled.yml

@@ -9,13 +9,14 @@ on:
   push:
     branches:
       - ci_*
+      - framework-agnostic-tokenizers
   repository_dispatch:
   schedule:
     - cron: "0 0 * * *"
 
 jobs:
   run_all_tests_torch_gpu:
-    runs-on: [self-hosted, single-gpu]
+    runs-on: [self-hosted, gpu, single-gpu]
     steps:
       - uses: actions/checkout@v2
 
@@ -109,7 +110,7 @@ jobs:
 
 
   run_all_tests_tf_gpu:
-    runs-on: [self-hosted, single-gpu]
+    runs-on: [self-hosted, gpu, single-gpu]
     steps:
       - uses: actions/checkout@v2
 
@@ -188,7 +189,7 @@ jobs:
           path: reports
           
   run_all_tests_torch_multi_gpu:
-    runs-on: [self-hosted, multi-gpu]
+    runs-on: [self-hosted, gpu, multi-gpu]
     steps:
       - uses: actions/checkout@v2
 
@@ -279,7 +280,7 @@ jobs:
           path: reports
 
   run_all_tests_tf_multi_gpu:
-    runs-on: [self-hosted, multi-gpu]
+    runs-on: [self-hosted, gpu, multi-gpu]
     steps:
       - uses: actions/checkout@v2
 

docs/source/model_doc/marian.rst

@@ -78,7 +78,7 @@ require 3 character language codes:
     tokenizer = MarianTokenizer.from_pretrained(model_name)
     print(tokenizer.supported_language_codes)
     model = MarianMTModel.from_pretrained(model_name)
-    translated = model.generate(**tokenizer.prepare_seq2seq_batch(src_text))
+    translated = model.generate(**tokenizer.prepare_seq2seq_batch(src_text, return_tensors="pt"))
     tgt_text = [tokenizer.decode(t, skip_special_tokens=True) for t in translated]
     # ["c'est une phrase en anglais que nous voulons traduire en français",
     # 'Isto deve ir para o português.',
@@ -150,7 +150,7 @@ Example of translating english to many romance languages, using old-style 2 char
     print(tokenizer.supported_language_codes)
 
     model = MarianMTModel.from_pretrained(model_name)
-    translated = model.generate(**tokenizer.prepare_seq2seq_batch(src_text))
+    translated = model.generate(**tokenizer.prepare_seq2seq_batch(src_text, return_tensors="pt"))
     tgt_text = [tokenizer.decode(t, skip_special_tokens=True) for t in translated]
     # ["c'est une phrase en anglais que nous voulons traduire en français", 'Isto deve ir para o português.',  'Y esto al español']
 

docs/source/model_doc/mbart.rst

@@ -44,7 +44,7 @@ the sequences for sequence-to-sequence fine-tuning.
 
     example_english_phrase = "UN Chief Says There Is No Military Solution in Syria"
     expected_translation_romanian = "Şeful ONU declară că nu există o soluţie militară în Siria"
-    batch = tokenizer.prepare_seq2seq_batch(example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian)
+    batch = tokenizer.prepare_seq2seq_batch(example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian, return_tensors="pt")
     model(input_ids=batch['input_ids'], labels=batch['labels']) # forward pass
 
 - Generation
@@ -58,7 +58,7 @@ the sequences for sequence-to-sequence fine-tuning.
     model = MBartForConditionalGeneration.from_pretrained("facebook/mbart-large-en-ro")
     tokenizer = MBartTokenizer.from_pretrained("facebook/mbart-large-en-ro")
     article = "UN Chief Says There Is No Military Solution in Syria"
-    batch = tokenizer.prepare_seq2seq_batch(src_texts=[article], src_lang="en_XX")
+    batch = tokenizer.prepare_seq2seq_batch(src_texts=[article], src_lang="en_XX", return_tensors="pt")
     translated_tokens = model.generate(**batch, decoder_start_token_id=tokenizer.lang_code_to_id["ro_RO"])
     translation = tokenizer.batch_decode(translated_tokens, skip_special_tokens=True)[0]
     assert translation == "Şeful ONU declară că nu există o soluţie militară în Siria"

docs/source/model_doc/pegasus.rst

@@ -78,7 +78,7 @@ Usage Example
     torch_device = 'cuda' if torch.cuda.is_available() else 'cpu'
     tokenizer = PegasusTokenizer.from_pretrained(model_name)
     model = PegasusForConditionalGeneration.from_pretrained(model_name).to(torch_device)
-    batch = tokenizer.prepare_seq2seq_batch(src_text, truncation=True, padding='longest').to(torch_device)
+    batch = tokenizer.prepare_seq2seq_batch(src_text, truncation=True, padding='longest', return_tensors="pt").to(torch_device)
     translated = model.generate(**batch)
     tgt_text = tokenizer.batch_decode(translated, skip_special_tokens=True)
     assert tgt_text[0] == "California's largest electricity provider has turned off power to hundreds of thousands of customers."

model_cards/tuner007/pegasus_paraphrase/README.md

@@ -11,7 +11,7 @@ tokenizer = PegasusTokenizer.from_pretrained(model_name)
 model = PegasusForConditionalGeneration.from_pretrained(model_name).to(torch_device)
 
 def get_response(input_text,num_return_sequences):
-  batch = tokenizer.prepare_seq2seq_batch([input_text],truncation=True,padding='longest',max_length=60).to(torch_device)
+  batch = tokenizer.prepare_seq2seq_batch([input_text],truncation=True,padding='longest',max_length=60, return_tensors="pt").to(torch_device)
   translated = model.generate(**batch,max_length=60,num_beams=10, num_return_sequences=num_return_sequences, temperature=1.5)
   tgt_text = tokenizer.batch_decode(translated, skip_special_tokens=True)
   return tgt_text

model_cards/tuner007/pegasus_qa/README.md

@@ -12,7 +12,7 @@ model = PegasusForConditionalGeneration.from_pretrained(model_name).to(torch_dev
 
 def get_answer(question, context):
   input_text = "question: %s text: %s" % (question,context)
-  batch = tokenizer.prepare_seq2seq_batch([input_text], truncation=True, padding='longest').to(torch_device)
+  batch = tokenizer.prepare_seq2seq_batch([input_text], truncation=True, padding='longest', return_tensors="pt").to(torch_device)
   translated = model.generate(**batch)
   tgt_text = tokenizer.batch_decode(translated, skip_special_tokens=True)
   return tgt_text[0]

scripts/fsmt/fsmt-make-super-tiny-model.py

@@ -58,7 +58,7 @@ tiny_model = FSMTForConditionalGeneration(config)
 print(f"num of params {tiny_model.num_parameters()}")
 
 # Test
-batch = tokenizer.prepare_seq2seq_batch(["Making tiny model"])
+batch = tokenizer.prepare_seq2seq_batch(["Making tiny model"], return_tensors="pt")
 outputs = tiny_model(**batch)
 
 print("test output:", len(outputs.logits[0]))

scripts/fsmt/fsmt-make-tiny-model.py

@@ -29,7 +29,7 @@ tiny_model = FSMTForConditionalGeneration(config)
 print(f"num of params {tiny_model.num_parameters()}")
 
 # Test
-batch = tokenizer.prepare_seq2seq_batch(["Making tiny model"])
+batch = tokenizer.prepare_seq2seq_batch(["Making tiny model"], return_tensors="pt")
 outputs = tiny_model(**batch)
 
 print("test output:", len(outputs.logits[0]))

src/transformers/models/bart/tokenization_bart.py

@@ -15,7 +15,9 @@
 
 from typing import List, Optional
 
-from ...tokenization_utils_base import BatchEncoding
+from transformers import add_start_docstrings
+
+from ...tokenization_utils_base import PREPARE_SEQ2SEQ_BATCH_DOCSTRING, BatchEncoding
 from ...utils import logging
 from ..roberta.tokenization_roberta import RobertaTokenizer
 
@@ -54,6 +56,7 @@ class BartTokenizer(RobertaTokenizer):
         "merges_file": {m: merges_url for m in _all_bart_models},
     }
 
+    @add_start_docstrings(PREPARE_SEQ2SEQ_BATCH_DOCSTRING)
     def prepare_seq2seq_batch(
         self,
         src_texts: List[str],
@@ -61,70 +64,10 @@ class BartTokenizer(RobertaTokenizer):
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
         padding: str = "longest",
-        return_tensors: str = "None",
+        return_tensors: str = None,
         truncation=True,
         **kwargs,
     ) -> BatchEncoding:
-        r"""
-
-        Prepare a batch that can be passed directly to an instance of :class:`~transformers.BartModel`.
-
-        Args:
-            src_texts: (:obj:`List[str]`):
-                List of documents to summarize or source language texts.
-            tgt_texts: (:obj:`List[str]`, `optional`):
-                List of summaries or target language texts.
-            max_length (:obj:`int`, `optional`):
-                Controls the maximum length for encoder inputs (documents to summarize or source language texts). If
-                left unset or set to :obj:`None`, this will use the predefined model maximum length if a maximum length
-                is required by one of the truncation/padding parameters. If the model has no specific maximum input
-                length (like XLNet) truncation/padding to a maximum length will be deactivated.
-            max_target_length (:obj:`int`, `optional`):
-                Controls the maximum length of decoder inputs (target language texts or summaries). If left unset or
-                set to :obj:`None`, this will use the max_length value.
-            padding (:obj:`bool`, :obj:`str` or :class:`~transformers.tokenization_utils_base.PaddingStrategy`, `optional`, defaults to :obj:`False`):
-                Activates and controls padding. Accepts the following values:
-
-                * :obj:`True` or :obj:`'longest'`: Pad to the longest sequence in the batch (or no padding if only a
-                  single sequence if provided).
-                * :obj:`'max_length'`: Pad to a maximum length specified with the argument :obj:`max_length` or to the
-                  maximum acceptable input length for the model if that argument is not provided.
-                * :obj:`False` or :obj:`'do_not_pad'` (default): No padding (i.e., can output a batch with sequences of
-                  different lengths).
-            return_tensors (:obj:`str` or :class:`~transformers.tokenization_utils_base.TensorType`, `optional`, defaults to "pt"):
-                If set, will return tensors instead of list of python integers. Acceptable values are:
-
-                * :obj:`'tf'`: Return TensorFlow :obj:`tf.constant` objects.
-                * :obj:`'pt'`: Return PyTorch :obj:`torch.Tensor` objects.
-                * :obj:`'np'`: Return Numpy :obj:`np.ndarray` objects.
-            truncation (:obj:`bool`, :obj:`str` or :class:`~transformers.tokenization_utils_base.TruncationStrategy`, `optional`, defaults to :obj:`True`):
-                Activates and controls truncation. Accepts the following values:
-
-                * :obj:`True` or :obj:`'longest_first'`: Truncate to a maximum length specified with the argument
-                  :obj:`max_length` or to the maximum acceptable input length for the model if that argument is not
-                  provided. This will truncate token by token, removing a token from the longest sequence in the pair
-                  if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`'only_first'`: Truncate to a maximum length specified with the argument :obj:`max_length` or to
-                  the maximum acceptable input length for the model if that argument is not provided. This will only
-                  truncate the first sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`'only_second'`: Truncate to a maximum length specified with the argument :obj:`max_length` or
-                  to the maximum acceptable input length for the model if that argument is not provided. This will only
-                  truncate the second sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`False` or :obj:`'do_not_truncate'` (default): No truncation (i.e., can output batch with
-                  sequence lengths greater than the model maximum admissible input size).
-            **kwargs:
-                Additional keyword arguments passed along to :obj:`self.__call__`.
-
-        Returns:
-            :class:`~transformers.BatchEncoding`: A :class:`~transformers.BatchEncoding` with the following fields:
-
-            - **input_ids** -- List of token ids to be fed to the encoder.
-            - **attention_mask** -- List of indices specifying which tokens should be attended to by the model.
-            - **labels** -- List of token ids for tgt_texts
-
-            The full set of keys ``[input_ids, attention_mask, labels]``, will only be returned if tgt_texts is passed.
-            Otherwise, input_ids, attention_mask will be the only keys.
-        """
         kwargs.pop("src_lang", None)
         kwargs.pop("tgt_lang", None)
         if max_length is None:

src/transformers/models/bart/tokenization_bart_fast.py

@@ -15,7 +15,9 @@
 
 from typing import List, Optional
 
-from ...tokenization_utils_base import BatchEncoding
+from transformers import add_start_docstrings
+
+from ...tokenization_utils_base import PREPARE_SEQ2SEQ_BATCH_DOCSTRING, BatchEncoding
 from ...utils import logging
 from ..roberta.tokenization_roberta_fast import RobertaTokenizerFast
 from .tokenization_bart import BartTokenizer
@@ -49,6 +51,7 @@ class BartTokenizerFast(RobertaTokenizerFast):
     }
     slow_tokenizer_class = BartTokenizer
 
+    @add_start_docstrings(PREPARE_SEQ2SEQ_BATCH_DOCSTRING)
     def prepare_seq2seq_batch(
         self,
         src_texts: List[str],
@@ -56,72 +59,10 @@ class BartTokenizerFast(RobertaTokenizerFast):
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
         padding: str = "longest",
-        return_tensors: str = "None",
+        return_tensors: Optional[str] = None,
         truncation=True,
         **kwargs,
     ) -> BatchEncoding:
-        r"""
-
-        Prepare a batch that can be passed directly to an instance of :class:`~transformers.BartModel`.
-
-        Args:
-            src_texts: (:obj:`List[str]`):
-                List of documents to summarize or source language texts.
-            tgt_texts: (:obj:`List[str]`, `optional`):
-                List of summaries or target language texts.
-            max_length (:obj:`int`, `optional`):
-                Controls the maximum length for encoder inputs (documents to summarize or source language texts). If
-                left unset or set to :obj:`None`, this will use the predefined model maximum length if a maximum length
-                is required by one of the truncation/padding parameters. If the model has no specific maximum input
-                length (like XLNet) truncation/padding to a maximum length will be deactivated.
-            max_target_length (:obj:`int`, `optional`):
-                Controls the maximum length of decoder inputs (target language texts or summaries). If left unset or
-                set to :obj:`None`, this will use the max_length value.
-            padding (:obj:`bool`, :obj:`str` or :class:`~transformers.tokenization_utils_base.PaddingStrategy`, `optional`, defaults to :obj:`False`):
-                Activates and controls padding. Accepts the following values:
-
-                * :obj:`True` or :obj:`'longest'`: Pad to the longest sequence in the batch (or no padding if only a
-                  single sequence if provided).
-                * :obj:`'max_length'`: Pad to a maximum length specified with the argument :obj:`max_length` or to the
-                  maximum acceptable input length for the model if that argument is not provided.
-                * :obj:`False` or :obj:`'do_not_pad'` (default): No padding (i.e., can output a batch with sequences of
-                  different lengths).
-            return_tensors (:obj:`str` or :class:`~transformers.tokenization_utils_base.TensorType`, `optional`, defaults to "pt"):
-                If set, will return tensors instead of list of python integers. Acceptable values are:
-
-                * :obj:`'tf'`: Return TensorFlow :obj:`tf.constant` objects.
-                * :obj:`'pt'`: Return PyTorch :obj:`torch.Tensor` objects.
-                * :obj:`'np'`: Return Numpy :obj:`np.ndarray` objects.
-            truncation (:obj:`bool`, :obj:`str` or :class:`~transformers.tokenization_utils_base.TruncationStrategy`, `optional`, defaults to :obj:`True`):
-                Activates and controls truncation. Accepts the following values:
-
-                * :obj:`True` or :obj:`'longest_first'`: Truncate to a maximum length specified with the argument
-                  :obj:`max_length` or to the maximum acceptable input length for the model if that argument is not
-                  provided. This will truncate token by token, removing a token from the longest sequence in the pair
-                  if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`'only_first'`: Truncate to a maximum length specified with the argument :obj:`max_length` or to
-                  the maximum acceptable input length for the model if that argument is not provided. This will only
-                  truncate the first sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`'only_second'`: Truncate to a maximum length specified with the argument :obj:`max_length` or
-                  to the maximum acceptable input length for the model if that argument is not provided. This will only
-                  truncate the second sequence of a pair if a pair of sequences (or a batch of pairs) is provided.
-                * :obj:`False` or :obj:`'do_not_truncate'` (default): No truncation (i.e., can output batch with
-                  sequence lengths greater than the model maximum admissible input size).
-            **kwargs:
-                Additional keyword arguments passed along to :obj:`self.__call__`.
-
-        Returns:
-            :class:`~transformers.BatchEncoding`: A :class:`~transformers.BatchEncoding` with the following fields:
-
-            - **input_ids** -- List of token ids to be fed to the encoder.
-            - **attention_mask** -- List of indices specifying which tokens should be attended to by the model.
-            - **decoder_input_ids** -- List of token ids to be fed to the decoder.
-            - **decoder_attention_mask** -- List of indices specifying which tokens should be attended to by the
-              decoder. This does not include causal mask, which is built by the model.
-
-            The full set of keys ``[input_ids, attention_mask, decoder_input_ids, decoder_attention_mask]``, will only
-            be returned if tgt_texts is passed. Otherwise, input_ids, attention_mask will be the only keys.
-        """
         if max_length is None:
             max_length = self.model_max_length
         model_inputs: BatchEncoding = self(

src/transformers/models/fsmt/tokenization_fsmt.py

@@ -491,7 +491,7 @@ class FSMTTokenizer(PreTrainedTokenizer):
         tgt_texts: Optional[List[str]] = None,
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
-        return_tensors: str = "pt",
+        return_tensors: Optional[str] = None,
         truncation=True,
         padding="longest",
         **unused,

src/transformers/models/marian/modeling_marian.py

@@ -41,7 +41,7 @@ class MarianMTModel(BartForConditionalGeneration):
 
         >>> model = MarianMTModel.from_pretrained(mname)
         >>> tok = MarianTokenizer.from_pretrained(mname)
-        >>> batch = tok.prepare_seq2seq_batch(src_texts=[sample_text])  # don't need tgt_text for inference
+        >>> batch = tok.prepare_seq2seq_batch(src_texts=[sample_text], return_tensors="pt")  # don't need tgt_text for inference
         >>> gen = model.generate(**batch)  # for forward pass: model(**batch)
         >>> words: List[str] = tok.batch_decode(gen, skip_special_tokens=True)  # returns "Where is the bus stop ?"
 

src/transformers/models/marian/tokenization_marian.py

@@ -70,7 +70,7 @@ class MarianTokenizer(PreTrainedTokenizer):
         >>> tok = MarianTokenizer.from_pretrained('Helsinki-NLP/opus-mt-en-de')
         >>> src_texts = [ "I am a small frog.", "Tom asked his teacher for advice."]
         >>> tgt_texts = ["Ich bin ein kleiner Frosch.", "Tom bat seinen Lehrer um Rat."]  # optional
-        >>> batch_enc: BatchEncoding = tok.prepare_seq2seq_batch(src_texts, tgt_texts=tgt_texts)
+        >>> batch_enc: BatchEncoding = tok.prepare_seq2seq_batch(src_texts, tgt_texts=tgt_texts, return_tensors="pt")
         >>> # keys  [input_ids, attention_mask, labels].
         >>> # model(**batch) should work
     """
@@ -175,7 +175,7 @@ class MarianTokenizer(PreTrainedTokenizer):
         tgt_texts: Optional[List[str]] = None,
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
-        return_tensors: str = "pt",
+        return_tensors: Optional[str] = None,
         truncation=True,
         padding="longest",
         **unused,

src/transformers/models/mbart/modeling_mbart.py

@@ -22,7 +22,7 @@ class MBartForConditionalGeneration(BartForConditionalGeneration):
         >>> model = MBartForConditionalGeneration.from_pretrained("facebook/mbart-large-en-ro")
         >>> tokenizer = MBartTokenizer.from_pretrained("facebook/mbart-large-en-ro")
         >>> article = "UN Chief Says There Is No Military Solution in Syria"
-        >>> batch = tokenizer.prepare_seq2seq_batch(src_texts=[article])
+        >>> batch = tokenizer.prepare_seq2seq_batch(src_texts=[article], return_tensors="pt")
         >>> translated_tokens = model.generate(**batch)
         >>> translation = tokenizer.batch_decode(translated_tokens, skip_special_tokens=True)[0]
         >>> assert translation == "Şeful ONU declară că nu există o soluţie militară în Siria"

src/transformers/models/mbart/tokenization_mbart.py

@@ -81,7 +81,7 @@ class MBartTokenizer(XLMRobertaTokenizer):
         >>> example_english_phrase = " UN Chief Says There Is No Military Solution in Syria"
         >>> expected_translation_romanian = "Şeful ONU declară că nu există o soluţie militară în Siria"
         >>> batch: dict = tokenizer.prepare_seq2seq_batch(
-        ...     example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian
+        ...     example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian, return_tensors="pt"
         ... )
 
     """
@@ -183,7 +183,7 @@ class MBartTokenizer(XLMRobertaTokenizer):
         max_target_length: Optional[int] = None,
         truncation: bool = True,
         padding: str = "longest",
-        return_tensors: str = "pt",
+        return_tensors: Optional[str] = None,
         add_prefix_space: bool = False,  # ignored
         **kwargs,
     ) -> BatchEncoding:

src/transformers/models/mbart/tokenization_mbart_fast.py

@@ -89,7 +89,7 @@ class MBartTokenizerFast(XLMRobertaTokenizerFast):
         >>> example_english_phrase = " UN Chief Says There Is No Military Solution in Syria"
         >>> expected_translation_romanian = "Şeful ONU declară că nu există o soluţie militară în Siria"
         >>> batch: dict = tokenizer.prepare_seq2seq_batch(
-        ...     example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian
+        ...     example_english_phrase, src_lang="en_XX", tgt_lang="ro_RO", tgt_texts=expected_translation_romanian, return_tensors="pt"
         ... )
     """
 
@@ -181,7 +181,7 @@ class MBartTokenizerFast(XLMRobertaTokenizerFast):
         max_target_length: Optional[int] = None,
         truncation: bool = True,
         padding: str = "longest",
-        return_tensors: str = "pt",
+        return_tensors: str = None,
         **kwargs,
     ) -> BatchEncoding:
         if max_length is None:

src/transformers/models/pegasus/modeling_pegasus.py

@@ -38,7 +38,7 @@ class PegasusForConditionalGeneration(BartForConditionalGeneration):
 
         >>> model = PegasusForConditionalGeneration.from_pretrained(mname)
         >>> tok = PegasusTokenizer.from_pretrained(mname)
-        >>> batch = tok.prepare_seq2seq_batch(src_texts=[PGE_ARTICLE])  # don't need tgt_text for inference
+        >>> batch = tok.prepare_seq2seq_batch(src_texts=[PGE_ARTICLE], return_tensors="pt")  # don't need tgt_text for inference
         >>> gen = model.generate(**batch)  # for forward pass: model(**batch)
         >>> summary: List[str] = tok.batch_decode(gen, skip_special_tokens=True)
         >>> assert summary == "California's largest electricity provider has turned off power to tens of thousands of customers."

src/transformers/models/pegasus/tokenization_pegasus.py

@@ -134,7 +134,7 @@ class PegasusTokenizer(ReformerTokenizer):
         tgt_texts: Optional[List[str]] = None,
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
-        return_tensors: str = "pt",
+        return_tensors: str = None,
         truncation=True,
         padding="longest",
         **unused,

src/transformers/models/pegasus/tokenization_pegasus_fast.py

@@ -95,7 +95,7 @@ class PegasusTokenizerFast(ReformerTokenizerFast):
         tgt_texts: Optional[List[str]] = None,
         max_length: Optional[int] = None,
         max_target_length: Optional[int] = None,
-        return_tensors: str = "pt",
+        return_tensors: str = None,
         truncation=True,
         padding="longest",
         **unused,