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RegexParser Class — langchain Architecture

Architecture documentation for the RegexParser class in regex.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  10925ecf_0028_c82d_a03e_3d51aac9fdf7["RegexParser"]
  ab3b196d_7ab2_81f1_0c38_feb56461e3e0["regex.py"]
  10925ecf_0028_c82d_a03e_3d51aac9fdf7 -->|defined in| ab3b196d_7ab2_81f1_0c38_feb56461e3e0
  6b76d616_b850_98bd_ad3f_c73f5ef1d7c0["is_lc_serializable()"]
  10925ecf_0028_c82d_a03e_3d51aac9fdf7 -->|method| 6b76d616_b850_98bd_ad3f_c73f5ef1d7c0
  2390897b_b64f_73c9_3f01_5b41d57446ee["_type()"]
  10925ecf_0028_c82d_a03e_3d51aac9fdf7 -->|method| 2390897b_b64f_73c9_3f01_5b41d57446ee
  d3f9af03_d5d7_b515_1553_90c42c111edf["parse()"]
  10925ecf_0028_c82d_a03e_3d51aac9fdf7 -->|method| d3f9af03_d5d7_b515_1553_90c42c111edf

Relationship Graph

Source Code

libs/langchain/langchain_classic/output_parsers/regex.py lines 9–40

class RegexParser(BaseOutputParser[dict[str, str]]):
    """Parse the output of an LLM call using a regex."""

    @classmethod
    @override
    def is_lc_serializable(cls) -> bool:
        return True

    regex: str
    """The regex to use to parse the output."""
    output_keys: list[str]
    """The keys to use for the output."""
    default_output_key: str | None = None
    """The default key to use for the output."""

    @property
    def _type(self) -> str:
        """Return the type key."""
        return "regex_parser"

    def parse(self, text: str) -> dict[str, str]:
        """Parse the output of an LLM call."""
        match = re.search(self.regex, text)
        if match:
            return {key: match.group(i + 1) for i, key in enumerate(self.output_keys)}
        if self.default_output_key is None:
            msg = f"Could not parse output: {text}"
            raise ValueError(msg)
        return {
            key: text if key == self.default_output_key else ""
            for key in self.output_keys
        }

Defined In

Source

Frequently Asked Questions

What is the RegexParser class?
RegexParser is a class in the langchain codebase, defined in libs/langchain/langchain_classic/output_parsers/regex.py.
Where is RegexParser defined?
RegexParser is defined in libs/langchain/langchain_classic/output_parsers/regex.py at line 9.

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