使用LangChain进行LLM/GPT开发 | LLM文档查询链

class BaseCombineDocumentsChain(Chain, ABC):
    """Base interface for chains combining documents."""

    @abstractmethod
    def combine_docs(self, docs: List[Document], **kwargs: Any) -> Tuple[str, dict]:
        """Combine documents into a single string."""

from langchain.prompts import PromptTemplate
from langchain.schema import StrOutputParser
from langchain_community.chat_models import ChatAnthropic
from langchain_core.prompts import format_document

doc_prompt = PromptTemplate.from_template("{page_content}")

chain = (
    {
        "content": lambda docs: "\n\n".join(
            format_document(doc, doc_prompt) for doc in docs
        )
    }
    | PromptTemplate.from_template("Summarize the following content:\n\n{content}")
    | ChatAnthropic()
    | StrOutputParser()
)

from langchain.schema import Document

text = """Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown.[1] A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.[2]

The United States tested the SNAP-10A nuclear reactor in space for 43 days in 1965,[3] with the next test of a nuclear reactor power system intended for space use occurring on 13 September 2012 with the Demonstration Using Flattop Fission (DUFF) test of the Kilopower reactor.[4]

After a ground-based test of the experimental 1965 Romashka reactor, which used uranium and direct thermoelectric conversion to electricity,[5] the USSR sent about 40 nuclear-electric satellites into space, mostly powered by the BES-5 reactor. The more powerful TOPAZ-II reactor produced 10 kilowatts of electricity.[3]

Examples of concepts that use nuclear power for space propulsion systems include the nuclear electric rocket (nuclear powered ion thruster(s)), the radioisotope rocket, and radioisotope electric propulsion (REP).[6] One of the more explored concepts is the nuclear thermal rocket, which was ground tested in the NERVA program. Nuclear pulse propulsion was the subject of Project Orion.[7]

Regulation and hazard prevention[edit]
After the ban of nuclear weapons in space by the Outer Space Treaty in 1967, nuclear power has been discussed at least since 1972 as a sensitive issue by states.[8] Particularly its potential hazards to Earth's environment and thus also humans has prompted states to adopt in the U.N. General Assembly the Principles Relevant to the Use of Nuclear Power Sources in Outer Space (1992), particularly introducing safety principles for launches and to manage their traffic.[8]

Benefits

Both the Viking 1 and Viking 2 landers used RTGs for power on the surface of Mars. (Viking launch vehicle pictured)
While solar power is much more commonly used, nuclear power can offer advantages in some areas. Solar cells, although efficient, can only supply energy to spacecraft in orbits where the solar flux is sufficiently high, such as low Earth orbit and interplanetary destinations close enough to the Sun. Unlike solar cells, nuclear power systems function independently of sunlight, which is necessary for deep space exploration. Nuclear-based systems can have less mass than solar cells of equivalent power, allowing more compact spacecraft that are easier to orient and direct in space. In the case of crewed spaceflight, nuclear power concepts that can power both life support and propulsion systems may reduce both cost and flight time.[9]

Selected applications and/or technologies for space include:

Radioisotope thermoelectric generator
Radioisotope heater unit
Radioisotope piezoelectric generator
Radioisotope rocket
Nuclear thermal rocket
Nuclear pulse propulsion
Nuclear electric rocket
"""

docs = [
    Document(
        page_content=split,
        metadata={"source": "https://en.wikipedia.org/wiki/Nuclear_power_in_space"},
    )
    for split in text.split()
]
print(chain.invoke(docs)

from functools import partial
from operator import itemgetter

from langchain.callbacks.manager import trace_as_chain_group
from langchain.prompts import PromptTemplate
from langchain.schema import StrOutputParser
from langchain_community.chat_models import ChatAnthropic
from langchain_core.prompts import format_document

# Chain for generating initial summary based on the first document

llm = ChatAnthropic()
first_prompt = PromptTemplate.from_template("Summarize this content:\n\n{context}")
document_prompt = PromptTemplate.from_template("{page_content}")
partial_format_doc = partial(format_document, prompt=document_prompt)
summary_chain = {"context": partial_format_doc} | first_prompt | llm | StrOutputParser()

# Chain for refining an existing summary based on
# an additional document

refine_prompt = PromptTemplate.from_template(
    "Here's your first summary: {prev_response}. "
    "Now add to it based on the following context: {context}"
)
refine_chain = (
    {
        "prev_response": itemgetter("prev_response"),
        "context": lambda x: partial_format_doc(x["doc"]),
    }
    | refine_prompt
    | llm
    | StrOutputParser()
)

# The final refine loop, which generates an initial summary
# then iteratively refines it based on each of the rest of the documents


def refine_loop(docs):
    with trace_as_chain_group("refine loop", inputs={"input": docs}) as manager:
        summary = summary_chain.invoke(
            docs[0], config={"callbacks": manager, "run_name": "initial summary"}
        )
        for i, doc in enumerate(docs[1:]):
            summary = refine_chain.invoke(
                {"prev_response": summary, "doc": doc},
                config={"callbacks": manager, "run_name": f"refine {i}"},
            )
        manager.on_chain_end({"output": summary})
    return summary

from langchain.schema import Document

text = """Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown.[1] A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.[2]

The United States tested the SNAP-10A nuclear reactor in space for 43 days in 1965,[3] with the next test of a nuclear reactor power system intended for space use occurring on 13 September 2012 with the Demonstration Using Flattop Fission (DUFF) test of the Kilopower reactor.[4]

After a ground-based test of the experimental 1965 Romashka reactor, which used uranium and direct thermoelectric conversion to electricity,[5] the USSR sent about 40 nuclear-electric satellites into space, mostly powered by the BES-5 reactor. The more powerful TOPAZ-II reactor produced 10 kilowatts of electricity.[3]

Examples of concepts that use nuclear power for space propulsion systems include the nuclear electric rocket (nuclear powered ion thruster(s)), the radioisotope rocket, and radioisotope electric propulsion (REP).[6] One of the more explored concepts is the nuclear thermal rocket, which was ground tested in the NERVA program. Nuclear pulse propulsion was the subject of Project Orion.[7]

Regulation and hazard prevention[edit]
After the ban of nuclear weapons in space by the Outer Space Treaty in 1967, nuclear power has been discussed at least since 1972 as a sensitive issue by states.[8] Particularly its potential hazards to Earth's environment and thus also humans has prompted states to adopt in the U.N. General Assembly the Principles Relevant to the Use of Nuclear Power Sources in Outer Space (1992), particularly introducing safety principles for launches and to manage their traffic.[8]

Benefits

Both the Viking 1 and Viking 2 landers used RTGs for power on the surface of Mars. (Viking launch vehicle pictured)
While solar power is much more commonly used, nuclear power can offer advantages in some areas. Solar cells, although efficient, can only supply energy to spacecraft in orbits where the solar flux is sufficiently high, such as low Earth orbit and interplanetary destinations close enough to the Sun. Unlike solar cells, nuclear power systems function independently of sunlight, which is necessary for deep space exploration. Nuclear-based systems can have less mass than solar cells of equivalent power, allowing more compact spacecraft that are easier to orient and direct in space. In the case of crewed spaceflight, nuclear power concepts that can power both life support and propulsion systems may reduce both cost and flight time.[9]

Selected applications and/or technologies for space include:

Radioisotope thermoelectric generator
Radioisotope heater unit
Radioisotope piezoelectric generator
Radioisotope rocket
Nuclear thermal rocket
Nuclear pulse propulsion
Nuclear electric rocket
"""

docs = [
    Document(
        page_content=split,
        metadata={"source": "https://en.wikipedia.org/wiki/Nuclear_power_in_space"},
    )
    for split in text.split("\n\n")
]
print(refine_loop(docs))

from functools import partial

from langchain.chains.combine_documents import collapse_docs, split_list_of_docs
from langchain.prompts import PromptTemplate
from langchain.schema import StrOutputParser
from langchain_community.chat_models import ChatAnthropic
from langchain_core.prompts import format_document
from langchain_core.runnables import RunnableParallel, RunnablePassthrough

llm = ChatAnthropic()

# Prompt and method for converting Document -> str.
document_prompt = PromptTemplate.from_template("{page_content}")
partial_format_document = partial(format_document, prompt=document_prompt)

# The chain we'll apply to each individual document.
# Returns a summary of the document.
map_chain = (
    {"context": partial_format_document}
    | PromptTemplate.from_template("Summarize this content:\n\n{context}")
    | llm
    | StrOutputParser()
)

# A wrapper chain to keep the original Document metadata
map_as_doc_chain = (
    RunnableParallel({"doc": RunnablePassthrough(), "content": map_chain})
    | (lambda x: Document(page_content=x["content"], metadata=x["doc"].metadata))
).with_config(run_name="Summarize (return doc)")

# The chain we'll repeatedly apply to collapse subsets of the documents
# into a consolidate document until the total token size of our
# documents is below some max size.
def format_docs(docs):
    return "\n\n".join(partial_format_document(doc) for doc in docs)


collapse_chain = (
    {"context": format_docs}
    | PromptTemplate.from_template("Collapse this content:\n\n{context}")
    | llm
    | StrOutputParser()
)


def get_num_tokens(docs):
    return llm.get_num_tokens(format_docs(docs))


def collapse(
    docs,
    config,
    token_max=4000,
):
    collapse_ct = 1
    while get_num_tokens(docs) > token_max:
        config["run_name"] = f"Collapse {collapse_ct}"
        invoke = partial(collapse_chain.invoke, config=config)
        split_docs = split_list_of_docs(docs, get_num_tokens, token_max)
        docs = [collapse_docs(_docs, invoke) for _docs in split_docs]
        collapse_ct += 1
    return docs

# The chain we'll use to combine our individual document summaries
# (or summaries over subset of documents if we had to collapse the map results)
# into a final summary.

reduce_chain = (
    {"context": format_docs}
    | PromptTemplate.from_template("Combine these summaries:\n\n{context}")
    | llm
    | StrOutputParser()
).with_config(run_name="Reduce")

# The final full chain
map_reduce = (map_as_doc_chain.map() | collapse | reduce_chain).with_config(
    run_name="Map reduce"
)

from langchain.schema import Document

text = """Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown.[1] A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.[2]

The United States tested the SNAP-10A nuclear reactor in space for 43 days in 1965,[3] with the next test of a nuclear reactor power system intended for space use occurring on 13 September 2012 with the Demonstration Using Flattop Fission (DUFF) test of the Kilopower reactor.[4]

After a ground-based test of the experimental 1965 Romashka reactor, which used uranium and direct thermoelectric conversion to electricity,[5] the USSR sent about 40 nuclear-electric satellites into space, mostly powered by the BES-5 reactor. The more powerful TOPAZ-II reactor produced 10 kilowatts of electricity.[3]

Examples of concepts that use nuclear power for space propulsion systems include the nuclear electric rocket (nuclear powered ion thruster(s)), the radioisotope rocket, and radioisotope electric propulsion (REP).[6] One of the more explored concepts is the nuclear thermal rocket, which was ground tested in the NERVA program. Nuclear pulse propulsion was the subject of Project Orion.[7]

Regulation and hazard prevention[edit]
After the ban of nuclear weapons in space by the Outer Space Treaty in 1967, nuclear power has been discussed at least since 1972 as a sensitive issue by states.[8] Particularly its potential hazards to Earth's environment and thus also humans has prompted states to adopt in the U.N. General Assembly the Principles Relevant to the Use of Nuclear Power Sources in Outer Space (1992), particularly introducing safety principles for launches and to manage their traffic.[8]

Benefits

Both the Viking 1 and Viking 2 landers used RTGs for power on the surface of Mars. (Viking launch vehicle pictured)
While solar power is much more commonly used, nuclear power can offer advantages in some areas. Solar cells, although efficient, can only supply energy to spacecraft in orbits where the solar flux is sufficiently high, such as low Earth orbit and interplanetary destinations close enough to the Sun. Unlike solar cells, nuclear power systems function independently of sunlight, which is necessary for deep space exploration. Nuclear-based systems can have less mass than solar cells of equivalent power, allowing more compact spacecraft that are easier to orient and direct in space. In the case of crewed spaceflight, nuclear power concepts that can power both life support and propulsion systems may reduce both cost and flight time.[9]

Selected applications and/or technologies for space include:

Radioisotope thermoelectric generator
Radioisotope heater unit
Radioisotope piezoelectric generator
Radioisotope rocket
Nuclear thermal rocket
Nuclear pulse propulsion
Nuclear electric rocket
"""

docs = [
    Document(
        page_content=split,
        metadata={"source": "https://en.wikipedia.org/wiki/Nuclear_power_in_space"},
    )
    for split in text.split("\n\n")
]


print(map_reduce.invoke(docs[0:1], config={"max_concurrency": 5}))

from langchain.output_parsers.openai_functions import PydanticOutputFunctionsParser
from langchain.prompts import PromptTemplate
from langchain.utils.openai_functions import convert_pydantic_to_openai_function
from langchain_community.chat_models import ChatOpenAI
from langchain_core.prompts import format_document
from langchain_core.pydantic_v1 import BaseModel, Field

# Chain to apply to each individual document. Chain
# provides an answer to the question based on the document
# and scores it's confidence in the answer.

map_prompt = PromptTemplate.from_template(
    "Answer the user question using the context."
    "\n\nContext:\n\n{context}\n\nQuestion: {question}"
)


class AnswerAndScore(BaseModel):
    """Return the answer to the question and a relevance score."""

    answer: str = Field(
        description="The answer to the question, which is based ONLY on the provided context."
    )
    score: float = Field(
        description="A 0.0-1.0 relevance score, where 1.0 indicates the provided context answers the question completely and 0.0 indicates the provided context does not answer the question at all."
    )


function = convert_pydantic_to_openai_function(AnswerAndScore)
map_chain = (
    map_prompt
    | ChatOpenAI().bind(
        temperature=0, functions=[function], function_call={"name": "AnswerAndScore"}
    )
    | PydanticOutputFunctionsParser(pydantic_schema=AnswerAndScore)
).with_config(run_name="Map")


# Final chain, which after answer and scoring based on
# each doc return the answer with the highest score.


def top_answer(scored_answers):
    return max(scored_answers, key=lambda x: x.score).answer


document_prompt = PromptTemplate.from_template("{page_content}")
map_rerank_chain = (
    (
        lambda x: [
            {
                "context": format_document(doc, document_prompt),
                "question": x["question"],
            }
            for doc in x["docs"]
        ]
    )
    | map_chain.map()
    | top_answer
).with_config(run_name="Map rerank")

from langchain.schema import Document

text = """Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown.[1] A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.[2]

The United States tested the SNAP-10A nuclear reactor in space for 43 days in 1965,[3] with the next test of a nuclear reactor power system intended for space use occurring on 13 September 2012 with the Demonstration Using Flattop Fission (DUFF) test of the Kilopower reactor.[4]

After a ground-based test of the experimental 1965 Romashka reactor, which used uranium and direct thermoelectric conversion to electricity,[5] the USSR sent about 40 nuclear-electric satellites into space, mostly powered by the BES-5 reactor. The more powerful TOPAZ-II reactor produced 10 kilowatts of electricity.[3]

Examples of concepts that use nuclear power for space propulsion systems include the nuclear electric rocket (nuclear powered ion thruster(s)), the radioisotope rocket, and radioisotope electric propulsion (REP).[6] One of the more explored concepts is the nuclear thermal rocket, which was ground tested in the NERVA program. Nuclear pulse propulsion was the subject of Project Orion.[7]

Regulation and hazard prevention[edit]
After the ban of nuclear weapons in space by the Outer Space Treaty in 1967, nuclear power has been discussed at least since 1972 as a sensitive issue by states.[8] Particularly its potential hazards to Earth's environment and thus also humans has prompted states to adopt in the U.N. General Assembly the Principles Relevant to the Use of Nuclear Power Sources in Outer Space (1992), particularly introducing safety principles for launches and to manage their traffic.[8]

Benefits

Both the Viking 1 and Viking 2 landers used RTGs for power on the surface of Mars. (Viking launch vehicle pictured)
While solar power is much more commonly used, nuclear power can offer advantages in some areas. Solar cells, although efficient, can only supply energy to spacecraft in orbits where the solar flux is sufficiently high, such as low Earth orbit and interplanetary destinations close enough to the Sun. Unlike solar cells, nuclear power systems function independently of sunlight, which is necessary for deep space exploration. Nuclear-based systems can have less mass than solar cells of equivalent power, allowing more compact spacecraft that are easier to orient and direct in space. In the case of crewed spaceflight, nuclear power concepts that can power both life support and propulsion systems may reduce both cost and flight time.[9]

Selected applications and/or technologies for space include:

Radioisotope thermoelectric generator
Radioisotope heater unit
Radioisotope piezoelectric generator
Radioisotope rocket
Nuclear thermal rocket
Nuclear pulse propulsion
Nuclear electric rocket
"""

docs = [
    Document(
        page_content=split,
        metadata={"source": "https://en.wikipedia.org/wiki/Nuclear_power_in_space"},
    )
    for split in text.split("\n\n")
]


print(
    map_rerank_chain.invoke({"docs": docs, "question": "How were the vikings powered"})
)