_to_chat_prompt() — langchain Function Reference

Architecture documentation for the _to_chat_prompt() function in huggingface.py from the langchain codebase.

Function python LangChainCore LanguageModelBase calls 1 called by 3

Entity Profile

LangChainCore→ LanguageModelBase→ _to_chat_prompt() — langchain Function Reference

Dependency Diagram

graph TD
  e77e373b_eb20_e566_3771_32082ca0dcc2["_to_chat_prompt()"]
  8cf0d6c0_abf8_3ee2_fd00_8bfc8c02058a["ChatHuggingFace"]
  e77e373b_eb20_e566_3771_32082ca0dcc2 -->|defined in| 8cf0d6c0_abf8_3ee2_fd00_8bfc8c02058a
  0e798408_eb45_2a4b_1ddb_579fdb006f07["_generate()"]
  0e798408_eb45_2a4b_1ddb_579fdb006f07 -->|calls| e77e373b_eb20_e566_3771_32082ca0dcc2
  f159f0cd_7dad_a4c8_5648_66f72caa1ece["_agenerate()"]
  f159f0cd_7dad_a4c8_5648_66f72caa1ece -->|calls| e77e373b_eb20_e566_3771_32082ca0dcc2
  ced9b52f_7bf4_4dc3_bc59_a48a9563d9bc["_stream()"]
  ced9b52f_7bf4_4dc3_bc59_a48a9563d9bc -->|calls| e77e373b_eb20_e566_3771_32082ca0dcc2
  e1c74edc_c011_1562_1576_22097f85b128["_to_chatml_format()"]
  e77e373b_eb20_e566_3771_32082ca0dcc2 -->|calls| e1c74edc_c011_1562_1576_22097f85b128
  style e77e373b_eb20_e566_3771_32082ca0dcc2 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/partners/huggingface/langchain_huggingface/chat_models/huggingface.py lines 947–964

    def _to_chat_prompt(
        self,
        messages: list[BaseMessage],
    ) -> str:
        """Convert a list of messages into a prompt format expected by wrapped LLM."""
        if not messages:
            msg = "At least one HumanMessage must be provided!"
            raise ValueError(msg)

        if not isinstance(messages[-1], HumanMessage):
            msg = "Last message must be a HumanMessage!"
            raise ValueError(msg)

        messages_dicts = [self._to_chatml_format(m) for m in messages]

        return self.tokenizer.apply_chat_template(
            messages_dicts, tokenize=False, add_generation_prompt=True
        )