少樣本提示

使用 LangChain 開發 LLM 應用

Jonathan Bennion

AI Engineer & LangChain Contributor

一般提示範本的限制

PromptTemplate + ChatPromptTemplate
✅ 適合少量範例
❌ 不適用大量範例
FewShotPromptTemplate

examples = [
    {
        "question": "..."
        "answer": "..."
    },
    ...
]

建立範例集

examples = [
    {
        "question": "Does Henry Campbell have any pets?",
        "answer": "Henry Campbell has a dog called Pluto."
    },
    ...
]

# Convert pandas DataFrame to list of dicts
examples = df.to_dict(orient="records")

格式化範例

from langchain_core.prompts import FewShotPromptTemplate, PromptTemplate


example_prompt = PromptTemplate.from_template("Question: {question}\n{answer}")

prompt = example_prompt.invoke({"question": "What is the capital of Italy?"
                                "answer": "Rome"})
print(prompt.text)

Question: What is the capital of Italy?
Rome

FewShotPromptTemplate

prompt_template = FewShotPromptTemplate(

    examples=examples,

    example_prompt=example_prompt,

    suffix="Question: {input}",

    input_variables=["input"]

)

examples：dict 清單
example_prompt：格式化範本
suffix：附加在輸入後的字尾
input_variables

叫用少樣本提示範本

prompt = prompt_template.invoke({"input": "What is the name of Henry Campbell's dog?"})

print(prompt.text)

Question: Does Henry Campbell have any pets?
Henry Campbell has a dog called Pluto.
...

Question: What is the name of Henry Campbell's dog?

與 chain 整合

llm = ChatOpenAI(model="gpt-4o-mini", api_key="...")


llm_chain = prompt_template | llm
response = llm_chain.invoke({"input": "What is the name of Henry Campbell's dog?"})

print(response.content)

The name of Henry Campbell's dog is Pluto.

一起來練習吧！

使用 LangChain 開發 LLM 應用