Refactor default chat template warnings (#30551)

* Temporarily silence warnings in apply_chat_template until we can properly deprecate default chat templates

* make fixup

* Move the default chat template warning into apply_chat_template itself

* make fixup

src/transformers/models/blenderbot/tokenization_blenderbot.py

@@ -411,13 +411,6 @@ class BlenderbotTokenizer(PreTrainedTokenizer):
         """
         A very simple chat template that just adds whitespace between messages.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{% if message['role'] == 'user' %}{{ ' ' }}{% endif %}"

src/transformers/models/blenderbot/tokenization_blenderbot_fast.py

@@ -293,13 +293,6 @@ class BlenderbotTokenizerFast(PreTrainedTokenizerFast):
         """
         A very simple chat template that just adds whitespace between messages.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{% if message['role'] == 'user' %}{{ ' ' }}{% endif %}"

src/transformers/models/blenderbot_small/tokenization_blenderbot_small.py

@@ -224,13 +224,6 @@ class BlenderbotSmallTokenizer(PreTrainedTokenizer):
         """
         A very simple chat template that just adds whitespace between messages.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{% if message['role'] == 'user' %}{{ ' ' }}{% endif %}"

src/transformers/models/blenderbot_small/tokenization_blenderbot_small_fast.py

@@ -104,13 +104,6 @@ class BlenderbotSmallTokenizerFast(PreTrainedTokenizerFast):
         """
         A very simple chat template that just adds whitespace between messages.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{% if message['role'] == 'user' %}{{ ' ' }}{% endif %}"

src/transformers/models/bloom/tokenization_bloom_fast.py

@@ -155,11 +155,4 @@ class BloomTokenizerFast(PreTrainedTokenizerFast):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"

src/transformers/models/code_llama/tokenization_code_llama.py

@@ -456,13 +456,6 @@ class CodeLlamaTokenizer(PreTrainedTokenizer):
         snippet](https://github.com/facebookresearch/llama/blob/556949fdfb72da27c2f4a40b7f0e4cf0b8153a28/llama/generation.py#L320-L362)
         in the original repository.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         template = (
             "{% if messages[0]['role'] == 'system' %}"
             "{% set loop_messages = messages[1:] %}"  # Extract system message if it's present

src/transformers/models/code_llama/tokenization_code_llama_fast.py

@@ -369,13 +369,6 @@ class CodeLlamaTokenizerFast(PreTrainedTokenizerFast):
         snippet](https://github.com/facebookresearch/llama/blob/556949fdfb72da27c2f4a40b7f0e4cf0b8153a28/llama/generation.py#L320-L362)
         in the original repository.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         template = (
             "{% if messages[0]['role'] == 'system' %}"
             "{% set loop_messages = messages[1:] %}"  # Extract system message if it's present

src/transformers/models/cohere/tokenization_cohere_fast.py

@@ -247,13 +247,6 @@ class CohereTokenizerFast(PreTrainedTokenizerFast):
         '<BOS_TOKEN><|START_OF_TURN_TOKEN|><|USER_TOKEN|>Hello, how are you?<|END_OF_TURN_TOKEN|><|START_OF_TURN_TOKEN|><|CHATBOT_TOKEN|>'
 
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         default_template = (
             "{{ bos_token }}"
             "{% if messages[0]['role'] == 'system' %}"

src/transformers/models/gpt2/tokenization_gpt2.py

@@ -336,11 +336,4 @@ class GPT2Tokenizer(PreTrainedTokenizer):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"

src/transformers/models/gpt2/tokenization_gpt2_fast.py

@@ -147,11 +147,5 @@ class GPT2TokenizerFast(PreTrainedTokenizerFast):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
+
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"

src/transformers/models/gpt_neox/tokenization_gpt_neox_fast.py

@@ -234,11 +234,4 @@ class GPTNeoXTokenizerFast(PreTrainedTokenizerFast):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"

src/transformers/models/gpt_neox_japanese/tokenization_gpt_neox_japanese.py

@@ -165,13 +165,6 @@ class GPTNeoXJapaneseTokenizer(PreTrainedTokenizer):
         """
         A simple chat template that just adds BOS/EOS tokens around messages while discarding role information.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{{ bos_token + eos_token + message.content + eos_token }}"

src/transformers/models/gpt_sw3/tokenization_gpt_sw3.py

@@ -301,13 +301,6 @@ class GPTSw3Tokenizer(PreTrainedTokenizer):
         This chat template formats messages like an instant messenger chat log, with "User:" and "Bot:" strings
         preceding messages. BOS tokens are added between all messages.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{{ eos_token }}{{ bos_token }}"
             "{% for message in messages %}"

src/transformers/models/gptsan_japanese/tokenization_gptsan_japanese.py

@@ -246,13 +246,6 @@ class GPTSanJapaneseTokenizer(PreTrainedTokenizer):
         A simple chat template that adds standard BOS, SEP and EOS tokens between messages while discarding role
         information.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{% if not loop.first %}{{ bos_token}}{% endif %}"

src/transformers/models/idefics2/processing_idefics2.py

@@ -284,8 +284,14 @@ class Idefics2Processor(ProcessorMixin):
             if self.chat_template is not None:
                 chat_template = self.chat_template
             else:
+                logger.warning_once(
+                    "No chat template is set for this processor, falling back to a default class-level template. This is "
+                    "very error-prone, because models are often trained with templates different from the class default! "
+                    "Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
+                    "point any code depending on them will stop working. We recommend setting a valid chat template before "
+                    "then to ensure that this model continues working without issues."
+                )
                 chat_template = self.default_chat_template
-
         return self.tokenizer.apply_chat_template(
             conversation, chat_template=chat_template, tokenize=tokenize, **kwargs
         )

src/transformers/models/llama/tokenization_llama.py

@@ -429,13 +429,6 @@ class LlamaTokenizer(PreTrainedTokenizer):
         snippet](https://github.com/facebookresearch/llama/blob/556949fdfb72da27c2f4a40b7f0e4cf0b8153a28/llama/generation.py#L320-L362)
         in the original repository.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         template = (
             "{% if messages[0]['role'] == 'system' %}"
             "{% set loop_messages = messages[1:] %}"  # Extract system message if it's present

src/transformers/models/llama/tokenization_llama_fast.py

@@ -261,13 +261,6 @@ class LlamaTokenizerFast(PreTrainedTokenizerFast):
         snippet](https://github.com/facebookresearch/llama/blob/556949fdfb72da27c2f4a40b7f0e4cf0b8153a28/llama/generation.py#L320-L362)
         in the original repository.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         template = (
             "{% if messages[0]['role'] == 'system' %}"
             "{% set loop_messages = messages[1:] %}"  # Extract system message if it's present

src/transformers/models/whisper/tokenization_whisper.py

@@ -815,13 +815,6 @@ class WhisperTokenizer(PreTrainedTokenizer):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"
 
     def get_decoder_prompt_ids(self, task=None, language=None, no_timestamps=True):

src/transformers/models/whisper/tokenization_whisper_fast.py

@@ -544,13 +544,6 @@ class WhisperTokenizerFast(PreTrainedTokenizerFast):
         """
         A simple chat template that ignores role information and just concatenates messages with EOS tokens.
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a default class-level template. "
-            "This is very error-prone, because models are often trained with templates different from the class "
-            "default! Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return "{% for message in messages %}" "{{ message.content }}{{ eos_token }}" "{% endfor %}"
 
     # Copied from transformers.models.whisper.tokenization_whisper.WhisperTokenizer.get_decoder_prompt_ids

src/transformers/tokenization_utils_base.py

@@ -1746,16 +1746,27 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
         if tokenizer_kwargs is None:
             tokenizer_kwargs = {}
 
+        using_default_template = False
+
         # First, handle the cases when the model has a dict of multiple templates
         if isinstance(self.chat_template, dict) or (
             self.chat_template is None and isinstance(self.default_chat_template, dict)
         ):
-            template_dict = self.chat_template or self.default_chat_template
+            if self.chat_template is not None:
+                template_dict = self.chat_template
+                using_default_dict = False
+            else:
+                template_dict = self.default_chat_template
+                using_default_dict = True
             if chat_template is not None and chat_template in template_dict:
                 # The user can pass the name of a template to the chat template argument instead of an entire template
                 chat_template = template_dict[chat_template]
+                if using_default_dict:
+                    using_default_template = True
             elif chat_template is None and "default" in template_dict:
                 chat_template = template_dict["default"]
+                if using_default_dict:
+                    using_default_template = True
             elif chat_template is None:
                 raise ValueError(
                     "This model has multiple chat templates with no default specified! Please either pass a chat "
@@ -1769,6 +1780,16 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
                 chat_template = self.chat_template
             else:
                 chat_template = self.default_chat_template
+                using_default_template = True
+
+        if using_default_template:
+            logger.warning_once(
+                "No chat template is set for this tokenizer, falling back to a default class-level template. This is "
+                "very error-prone, because models are often trained with templates different from the class default! "
+                "Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
+                "point any code depending on them will stop working. We recommend setting a valid chat template before "
+                "then to ensure that this model continues working without issues."
+            )
 
         # Compilation function uses a cache to avoid recompiling the same template
         compiled_template = self._compile_jinja_template(chat_template)
@@ -1840,13 +1861,6 @@ class PreTrainedTokenizerBase(SpecialTokensMixin, PushToHubMixin):
         This template formats inputs in the standard ChatML format. See
         https://github.com/openai/openai-python/blob/main/chatml.md
         """
-        logger.warning_once(
-            "No chat template is set for this tokenizer, falling back to a ChatML template. "
-            "This is very error-prone, because most models are not trained with a ChatML template!"
-            "Default chat templates are a legacy feature and will be removed in Transformers v4.43, at which "
-            "point any code depending on them will stop working. We recommend setting a valid chat template before "
-            "then to ensure that this model continues working without issues."
-        )
         return (
             "{% for message in messages %}"
             "{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}"