format() — langchain Function Reference

Architecture documentation for the format() function in chat.py from the langchain codebase.

Function python PromptManagement ChatTemplates calls 2 called by 3

Entity Profile

PromptManagement→ ChatTemplates→ format() — langchain Function Reference

Dependency Diagram

graph TD
  4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1["format()"]
  894611e5_5039_7621_4673_821d0b9b6f17["_StringImageMessagePromptTemplate"]
  4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1 -->|defined in| 894611e5_5039_7621_4673_821d0b9b6f17
  294ab761_8d23_d66d_6743_cc31d8ac0289["format_messages()"]
  294ab761_8d23_d66d_6743_cc31d8ac0289 -->|calls| 4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1
  da277d85_ccb4_d225_0110_0e1adda5fb46["format()"]
  da277d85_ccb4_d225_0110_0e1adda5fb46 -->|calls| 4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1
  08b4874f_15ee_e20e_22dd_dc40f35fb150["format()"]
  08b4874f_15ee_e20e_22dd_dc40f35fb150 -->|calls| 4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1
  51e4c8c4_03c1_4bf3_6d35_36e10545e164["append()"]
  4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1 -->|calls| 51e4c8c4_03c1_4bf3_6d35_36e10545e164
  da277d85_ccb4_d225_0110_0e1adda5fb46["format()"]
  4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1 -->|calls| da277d85_ccb4_d225_0110_0e1adda5fb46
  style 4d5e2501_6d84_a2a3_49d1_fa84af2fe2d1 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/prompts/chat.py lines 583–612

    def format(self, **kwargs: Any) -> BaseMessage:
        """Format the prompt template.

        Args:
            **kwargs: Keyword arguments to use for formatting.

        Returns:
            Formatted message.
        """
        if isinstance(self.prompt, StringPromptTemplate):
            text = self.prompt.format(**kwargs)
            return self._msg_class(
                content=text, additional_kwargs=self.additional_kwargs
            )
        content: list = []
        for prompt in self.prompt:
            inputs = {var: kwargs[var] for var in prompt.input_variables}
            if isinstance(prompt, StringPromptTemplate):
                formatted_text: str = prompt.format(**inputs)
                if formatted_text != "":
                    content.append({"type": "text", "text": formatted_text})
            elif isinstance(prompt, ImagePromptTemplate):
                formatted_image: ImageURL = prompt.format(**inputs)
                content.append({"type": "image_url", "image_url": formatted_image})
            elif isinstance(prompt, DictPromptTemplate):
                formatted_dict: dict[str, Any] = prompt.format(**inputs)
                content.append(formatted_dict)
        return self._msg_class(
            content=content, additional_kwargs=self.additional_kwargs
        )