令牌计数

LangChain提供了一个上下文管理器，允许您计算令牌数量。

import asyncio

from langchain.callbacks import get_openai_callback
from langchain.llms import OpenAI

llm = OpenAI(temperature=0)
with get_openai_callback() as cb:
    llm("What is the square root of 4?")

total_tokens = cb.total_tokens
assert total_tokens > 0

with get_openai_callback() as cb:
    llm("What is the square root of 4?")
    llm("What is the square root of 4?")

assert cb.total_tokens == total_tokens * 2

# 您可以在上下文管理器内启动并发运行
with get_openai_callback() as cb:
    await asyncio.gather(
        *[llm.agenerate(["What is the square root of 4?"]) for _ in range(3)]
    )

assert cb.total_tokens == total_tokens * 3

# 上下文管理器是并发安全的
task = asyncio.create_task(llm.agenerate(["What is the square root of 4?"]))
with get_openai_callback() as cb:
    await llm.agenerate(["What is the square root of 4?"])

await task
assert cb.total_tokens == total_tokens

API参考：

• get_openai_callback 来自 langchain.callbacks
• OpenAI 来自 langchain.llms