CommaSeparatedListOutputParser Class — langchain Architecture

Architecture documentation for the CommaSeparatedListOutputParser class in list.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02["CommaSeparatedListOutputParser"]
  137024f5_2b01_9c8f_64f4_357c533282c7["ListOutputParser"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|extends| 137024f5_2b01_9c8f_64f4_357c533282c7
  39460b97_96ad_60ff_34e4_145e3ec6b305["list.py"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|defined in| 39460b97_96ad_60ff_34e4_145e3ec6b305
  71fc7558_af6e_68ab_2dc8_a1454c7b147c["is_lc_serializable()"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|method| 71fc7558_af6e_68ab_2dc8_a1454c7b147c
  31d2b6e2_95a4_61a8_e6cd_b8e772ad90d9["get_lc_namespace()"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|method| 31d2b6e2_95a4_61a8_e6cd_b8e772ad90d9
  bf2e9af3_be3c_ef07_4817_5e470685f9ef["get_format_instructions()"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|method| bf2e9af3_be3c_ef07_4817_5e470685f9ef
  37c83659_6d94_9955_c8ef_5d62476308d7["parse()"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|method| 37c83659_6d94_9955_c8ef_5d62476308d7
  b3a2d7c4_7ff5_6e9b_7983_3d0acb928117["_type()"]
  570c1ea0_9f3c_ba85_f3ca_127bf9b2bf02 -->|method| b3a2d7c4_7ff5_6e9b_7983_3d0acb928117

Relationship Graph

Source Code

libs/core/langchain_core/output_parsers/list.py lines 139–185

class CommaSeparatedListOutputParser(ListOutputParser):
    """Parse the output of a model to a comma-separated list."""

    @classmethod
    def is_lc_serializable(cls) -> bool:
        """Return `True` as this class is serializable."""
        return True

    @classmethod
    def get_lc_namespace(cls) -> list[str]:
        """Get the namespace of the LangChain object.

        Returns:
            `["langchain", "output_parsers", "list"]`
        """
        return ["langchain", "output_parsers", "list"]

    @override
    def get_format_instructions(self) -> str:
        """Return the format instructions for the comma-separated list output."""
        return (
            "Your response should be a list of comma separated values, "
            "eg: `foo, bar, baz` or `foo,bar,baz`"
        )

    @override
    def parse(self, text: str) -> list[str]:
        """Parse the output of an LLM call.

        Args:
            text: The output of an LLM call.

        Returns:
            A list of strings.
        """
        try:
            reader = csv.reader(
                StringIO(text), quotechar='"', delimiter=",", skipinitialspace=True
            )
            return [item for sublist in reader for item in sublist]
        except csv.Error:
            # Keep old logic for backup
            return [part.strip() for part in text.split(",")]

    @property
    def _type(self) -> str:
        return "comma-separated-list"