codekingpro/portable-devtools

1"""String output parser."""2 3from typing_extensions import override4 5from langchain_core.output_parsers.transform import BaseTransformOutputParser6 7 8class StrOutputParser(BaseTransformOutputParser[str]):9    """Extract text content from model outputs as a string.10 11    Converts model outputs (such as `AIMessage` or `AIMessageChunk` objects) into plain12    text strings. It's the simplest output parser and is useful when you need string13    responses for downstream processing, display, or storage.14 15    Supports streaming, yielding text chunks as they're generated by the model.16 17    Example:18        ```python19        from langchain_core.output_parsers import StrOutputParser20        from langchain_openai import ChatOpenAI21 22        model = ChatOpenAI(model="gpt-4o")23        parser = StrOutputParser()24 25        # Get string output from a model26        message = model.invoke("Tell me a joke")27        result = parser.invoke(message)28        print(result)  # plain string29 30        # With streaming - use transform() to process a stream31        stream = model.stream("Tell me a story")32        for chunk in parser.transform(stream):33            print(chunk, end="", flush=True)34        ```35    """36 37    @classmethod38    def is_lc_serializable(cls) -> bool:39        """`StrOutputParser` is serializable.40 41        Returns:42            `True`43        """44        return True45 46    @classmethod47    def get_lc_namespace(cls) -> list[str]:48        """Get the namespace of the LangChain object.49 50        Returns:51            `["langchain", "schema", "output_parser"]`52        """53        return ["langchain", "schema", "output_parser"]54 55    @property56    def _type(self) -> str:57        """Return the output parser type for serialization."""58        return "default"59 60    @override61    def parse(self, text: str) -> str:62        """Returns the input text with no changes."""63        return text64