| from __future__ import annotations |
|
|
| import re |
| from typing import Dict, Optional |
|
|
| from langchain_core.output_parsers import BaseOutputParser |
|
|
|
|
| class RegexDictParser(BaseOutputParser[Dict[str, str]]): |
| """Parse the output of an LLM call into a Dictionary using a regex.""" |
|
|
| regex_pattern: str = r"{}:\s?([^.'\n']*)\.?" |
| """The regex pattern to use to parse the output.""" |
| output_key_to_format: Dict[str, str] |
| """The keys to use for the output.""" |
| no_update_value: Optional[str] = None |
| """The default key to use for the output.""" |
|
|
| @property |
| def _type(self) -> str: |
| """Return the type key.""" |
| return "regex_dict_parser" |
|
|
| def parse(self, text: str) -> Dict[str, str]: |
| """Parse the output of an LLM call.""" |
| result = {} |
| for output_key, expected_format in self.output_key_to_format.items(): |
| specific_regex = self.regex_pattern.format(re.escape(expected_format)) |
| matches = re.findall(specific_regex, text) |
| if not matches: |
| raise ValueError( |
| f"No match found for output key: {output_key} with expected format \ |
| {expected_format} on text {text}" |
| ) |
| elif len(matches) > 1: |
| raise ValueError( |
| f"Multiple matches found for output key: {output_key} with \ |
| expected format {expected_format} on text {text}" |
| ) |
| elif ( |
| self.no_update_value is not None and matches[0] == self.no_update_value |
| ): |
| continue |
| else: |
| result[output_key] = matches[0] |
| return result |
|
|
