Source code for langchain.output_parsers.retry
from __future__ import annotations
from typing import TypeVar
from langchain.base_language import BaseLanguageModel
from langchain.chains.llm import LLMChain
from langchain.prompts.base import BasePromptTemplate
from langchain.prompts.prompt import PromptTemplate
from langchain.schema import (
    BaseOutputParser,
    OutputParserException,
    PromptValue,
)
NAIVE_COMPLETION_RETRY = """Prompt:
{prompt}
Completion:
{completion}
Above, the Completion did not satisfy the constraints given in the Prompt.
Please try again:"""
NAIVE_COMPLETION_RETRY_WITH_ERROR = """Prompt:
{prompt}
Completion:
{completion}
Above, the Completion did not satisfy the constraints given in the Prompt.
Details: {error}
Please try again:"""
NAIVE_RETRY_PROMPT = PromptTemplate.from_template(NAIVE_COMPLETION_RETRY)
NAIVE_RETRY_WITH_ERROR_PROMPT = PromptTemplate.from_template(
    NAIVE_COMPLETION_RETRY_WITH_ERROR
)
T = TypeVar("T")
[docs]class RetryOutputParser(BaseOutputParser[T]):
    """Wraps a parser and tries to fix parsing errors.
    Does this by passing the original prompt and the completion to another
    LLM, and telling it the completion did not satisfy criteria in the prompt.
    """
    parser: BaseOutputParser[T]
    retry_chain: LLMChain
[docs]    @classmethod
    def from_llm(
        cls,
        llm: BaseLanguageModel,
        parser: BaseOutputParser[T],
        prompt: BasePromptTemplate = NAIVE_RETRY_PROMPT,
    ) -> RetryOutputParser[T]:
        chain = LLMChain(llm=llm, prompt=prompt)
rtdocs_stable/api.python.langchain.com/en/stable/_modules/langchain/output_parsers/retry.html