Source code for langchain.callbacks.streaming_stdout_final_only
"""回调处理程序在新的llm令牌上流向标准输出。"""
import sys
from typing import Any, Dict, List, Optional
from langchain_core.callbacks import StreamingStdOutCallbackHandler
DEFAULT_ANSWER_PREFIX_TOKENS = ["Final", "Answer", ":"]
[docs]class FinalStreamingStdOutCallbackHandler(StreamingStdOutCallbackHandler):
"""代理流处理程序的回调函数。
仅适用于支持流式处理的LLM代理。
仅代理的最终输出将被流式传输。"""
[docs] def append_to_last_tokens(self, token: str) -> None:
self.last_tokens.append(token)
self.last_tokens_stripped.append(token.strip())
if len(self.last_tokens) > len(self.answer_prefix_tokens):
self.last_tokens.pop(0)
self.last_tokens_stripped.pop(0)
[docs] def check_if_answer_reached(self) -> bool:
if self.strip_tokens:
return self.last_tokens_stripped == self.answer_prefix_tokens_stripped
else:
return self.last_tokens == self.answer_prefix_tokens
[docs] def __init__(
self,
*,
answer_prefix_tokens: Optional[List[str]] = None,
strip_tokens: bool = True,
stream_prefix: bool = False,
) -> None:
"""实例化FinalStreamingStdOutCallbackHandler。
参数:
answer_prefix_tokens:前缀答案的标记序列。
默认值为["Final", "Answer", ":"]
strip_tokens:在比较answer_prefix_tokens和最后一个标记时,是否忽略空格和换行符?
stream_prefix:答案前缀本身是否也应该被流式传输?
"""
super().__init__()
if answer_prefix_tokens is None:
self.answer_prefix_tokens = DEFAULT_ANSWER_PREFIX_TOKENS
else:
self.answer_prefix_tokens = answer_prefix_tokens
if strip_tokens:
self.answer_prefix_tokens_stripped = [
token.strip() for token in self.answer_prefix_tokens
]
else:
self.answer_prefix_tokens_stripped = self.answer_prefix_tokens
self.last_tokens = [""] * len(self.answer_prefix_tokens)
self.last_tokens_stripped = [""] * len(self.answer_prefix_tokens)
self.strip_tokens = strip_tokens
self.stream_prefix = stream_prefix
self.answer_reached = False
[docs] def on_llm_start(
self, serialized: Dict[str, Any], prompts: List[str], **kwargs: Any
) -> None:
"""LLM 开始运行时运行。"""
self.answer_reached = False
[docs] def on_llm_new_token(self, token: str, **kwargs: Any) -> None:
"""在新的LLM令牌上运行。仅在流式处理启用时可用。"""
# Remember the last n tokens, where n = len(answer_prefix_tokens)
self.append_to_last_tokens(token)
# Check if the last n tokens match the answer_prefix_tokens list ...
if self.check_if_answer_reached():
self.answer_reached = True
if self.stream_prefix:
for t in self.last_tokens:
sys.stdout.write(t)
sys.stdout.flush()
return
# ... if yes, then print tokens from now on
if self.answer_reached:
sys.stdout.write(token)
sys.stdout.flush()