Tony20100/langchain_full huggingface dataset:
# -> [4, 6, 8]
Parameters
others (Union[Runnable[Any, Other], Callable[[Any], Other]]) – 
name (Optional[str]) – 
Return type
RunnableSerializable[Input, Other]
prepare(config: Optional[RunnableConfig] = None) → Tuple[Runnable[Input, Output], RunnableConfig]¶
Parameters
config (Optional[RunnableConfig]) – 
Return type
Tuple[Runnable[Input, Output], RunnableConfig]
classmethod schema(by_alias: bool = True, ref_template: unicode = '#/definitions/{model}') → DictStrAny¶
Parameters
by_alias (bool) – 
ref_template (unicode) – 
Return type
DictStrAny
classmethod schema_json(*, by_alias: bool = True, ref_template: unicode = '#/definitions/{model}', **dumps_kwargs: Any) → unicode¶
Parameters
by_alias (bool) – 
ref_template (unicode) – 
dumps_kwargs (Any) – 
Return type
unicode
stream(input: Input, config: Optional[RunnableConfig] = None, **kwargs: Optional[Any]) → Iterator[Output]¶
Default implementation of stream, which calls invoke.
Subclasses should override this method if they support streaming output.
Parameters
input (Input) – 
config (Optional[RunnableConfig]) – 
kwargs (Optional[Any]) – 
Return type
Iterator[Output]
to_json() → Union[SerializedConstructor, SerializedNotImplemented]¶
Serialize the runnable to JSON.
Return type
Union[SerializedConstructor, SerializedNotImplemented]
to_json_not_implemented() → SerializedNotImplemented¶
Return type
SerializedNotImplemented
transform(input: Iterator[Input], config: Optional[RunnableConfig] = None, **kwargs: Optional[Any]) → Iterator[Output]¶
langchain_core.runnables.config.get_executor_for_config¶
langchain_core.runnables.config.get_executor_for_config(config: Optional[RunnableConfig]) → Generator[Executor, None, None][source]¶
Get an executor for a config.
Parameters
config (RunnableConfig) – The config.
Yields
Generator[Executor, None, None] – The executor.
Return type
Generator[Executor, None, None]
langchain_core.runnables.base.RunnableGenerator¶
class langchain_core.runnables.base.RunnableGenerator(transform: Union[Callable[[Iterator[Input]], Iterator[Output]], Callable[[AsyncIterator[Input]], AsyncIterator[Output]]], atransform: Optional[Callable[[AsyncIterator[Input]], AsyncIterator[Output]]] = None)[source]¶
Runnable that runs a generator function.
RunnableGenerators can be instantiated directly or by using a generator within
a sequence.
RunnableGenerators can be used to implement custom behavior, such as custom output
parsers, while preserving streaming capabilities. Given a generator function with
a signature Iterator[A] -> Iterator[B], wrapping it in a RunnableGenerator allows
it to emit output chunks as soon as they are streamed in from the previous step.
Note that if a generator function has a signature A -> Iterator[B], such that it
requires its input from the previous step to be completed before emitting chunks
(e.g., most LLMs need the entire prompt available to start generating), it can
instead be wrapped in a RunnableLambda.
Here is an example to show the basic mechanics of a RunnableGenerator:
from typing import Any, AsyncIterator, Iterator
from langchain_core.runnables import RunnableGenerator
def gen(input: Iterator[Any]) -> Iterator[str]:
    for token in ["Have", " a", " nice", " day"]:
        yield token
runnable = RunnableGenerator(gen)
runnable.invoke(None)  # "Have a nice day"
list(runnable.stream(None))  # ["Have", " a", " nice", " day"]
runnable.batch([None, None])  # ["Have a nice day", "Have a nice day"]
# Async version:
async def agen(input: AsyncIterator[Any]) -> AsyncIterator[str]:
    for token in ["Have", " a", " nice", " day"]:
for token in ["Have", " a", " nice", " day"]:
        yield token
runnable = RunnableGenerator(agen)
await runnable.ainvoke(None)  # "Have a nice day"
[p async for p in runnable.astream(None)] # ["Have", " a", " nice", " day"]
RunnableGenerator makes it easy to implement custom behavior within a streaming
context. Below we show an example:
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.runnables import RunnableGenerator, RunnableLambda
from langchain_openai import ChatOpenAI
from langchain_core.output_parsers import StrOutputParser
model = ChatOpenAI()
chant_chain = (
    ChatPromptTemplate.from_template("Give me a 3 word chant about {topic}")
    | model
    | StrOutputParser()
)
def character_generator(input: Iterator[str]) -> Iterator[str]:
    for token in input:
        if "," in token or "." in token:
            yield "👏" + token
        else:
            yield token
runnable = chant_chain | character_generator
assert type(runnable.last) is RunnableGenerator
"".join(runnable.stream({"topic": "waste"})) # Reduce👏, Reuse👏, Recycle👏.
# Note that RunnableLambda can be used to delay streaming of one step in a
# sequence until the previous step is finished:
def reverse_generator(input: str) -> Iterator[str]:
    # Yield characters of input in reverse order.
    for character in input[::-1]:
        yield character
runnable = chant_chain | RunnableLambda(reverse_generator)
"".join(runnable.stream({"topic": "waste"}))  # ".elcycer ,esuer ,ecudeR"
Attributes
InputType
Attributes
InputType
The type of input this runnable accepts specified as a type annotation.
OutputType
The type of output this runnable produces specified as a type annotation.
config_specs
List configurable fields for this runnable.
input_schema
The type of input this runnable accepts specified as a pydantic model.
name
The name of the runnable.
output_schema
The type of output this runnable produces specified as a pydantic model.
Methods
__init__(transform[, atransform])
abatch(inputs[, config, return_exceptions])
Default implementation runs ainvoke in parallel using asyncio.gather.
abatch_as_completed(inputs[, config, ...])
Run ainvoke in parallel on a list of inputs, yielding results as they complete.
ainvoke(input[, config])
Default implementation of ainvoke, calls invoke from a thread.
assign(**kwargs)
Assigns new fields to the dict output of this runnable.
astream(input[, config])
Default implementation of astream, which calls ainvoke.
astream_events(input[, config, ...])
[Beta] Generate a stream of events.
astream_log(input[, config, diff, ...])
Stream all output from a runnable, as reported to the callback system.
atransform(input[, config])
Default implementation of atransform, which buffers input and calls astream.
batch(inputs[, config, return_exceptions])
Default implementation runs invoke in parallel using a thread pool executor.
batch_as_completed(inputs[, config, ...])
Run invoke in parallel on a list of inputs, yielding results as they complete.
bind(**kwargs)
Bind arguments to a Runnable, returning a new Runnable.
config_schema(*[, include])
The type of config this runnable accepts specified as a pydantic model.
get_graph([config])
get_graph([config])
Return a graph representation of this runnable.
get_input_schema([config])
Get a pydantic model that can be used to validate input to the runnable.
get_name([suffix, name])
Get the name of the runnable.
get_output_schema([config])
Get a pydantic model that can be used to validate output to the runnable.
get_prompts([config])
invoke(input[, config])
Transform a single input into an output.
map()
Return a new Runnable that maps a list of inputs to a list of outputs, by calling invoke() with each input.
pick(keys)
Pick keys from the dict output of this runnable.
pipe(*others[, name])
Compose this Runnable with Runnable-like objects to make a RunnableSequence.
stream(input[, config])
Default implementation of stream, which calls invoke.
transform(input[, config])
Default implementation of transform, which buffers input and then calls stream.
with_alisteners(*[, on_start, on_end, on_error])
Bind asynchronous lifecycle listeners to a Runnable, returning a new Runnable.
with_config([config])
Bind config to a Runnable, returning a new Runnable.
with_fallbacks(fallbacks, *[, ...])
Add fallbacks to a runnable, returning a new Runnable.
with_listeners(*[, on_start, on_end, on_error])
Bind lifecycle listeners to a Runnable, returning a new Runnable.
with_retry(*[, retry_if_exception_type, ...])
Create a new Runnable that retries the original runnable on exceptions.
with_types(*[, input_type, output_type])
Bind input and output types to a Runnable, returning a new Runnable.
Parameters
Bind input and output types to a Runnable, returning a new Runnable.
Parameters
transform (Union[Callable[[Iterator[Input]], Iterator[Output]], Callable[[AsyncIterator[Input]], AsyncIterator[Output]]]) – 
atransform (Optional[Callable[[AsyncIterator[Input]], AsyncIterator[Output]]]) – 
__init__(transform: Union[Callable[[Iterator[Input]], Iterator[Output]], Callable[[AsyncIterator[Input]], AsyncIterator[Output]]], atransform: Optional[Callable[[AsyncIterator[Input]], AsyncIterator[Output]]] = None) → None[source]¶
Parameters
transform (Union[Callable[[Iterator[Input]], Iterator[Output]], Callable[[AsyncIterator[Input]], AsyncIterator[Output]]]) – 
atransform (Optional[Callable[[AsyncIterator[Input]], AsyncIterator[Output]]]) – 
Return type
None
async abatch(inputs: List[Input], config: Optional[Union[RunnableConfig, List[RunnableConfig]]] = None, *, return_exceptions: bool = False, **kwargs: Optional[Any]) → List[Output]¶
Default implementation runs ainvoke in parallel using asyncio.gather.
The default implementation of batch works well for IO bound runnables.
Subclasses should override this method if they can batch more efficiently;
e.g., if the underlying runnable uses an API which supports a batch mode.
Parameters
inputs (List[Input]) – 
config (Optional[Union[RunnableConfig, List[RunnableConfig]]]) – 
return_exceptions (bool) – 
kwargs (Optional[Any]) – 
Return type
List[Output]
kwargs (Optional[Any]) – 
Return type
List[Output]
async abatch_as_completed(inputs: Sequence[Input], config: Optional[Union[RunnableConfig, Sequence[RunnableConfig]]] = None, *, return_exceptions: bool = False, **kwargs: Optional[Any]) → AsyncIterator[Tuple[int, Union[Output, Exception]]]¶
Run ainvoke in parallel on a list of inputs,
yielding results as they complete.
Parameters
inputs (Sequence[Input]) – 
config (Optional[Union[RunnableConfig, Sequence[RunnableConfig]]]) – 
return_exceptions (bool) – 
kwargs (Optional[Any]) – 
Return type
AsyncIterator[Tuple[int, Union[Output, Exception]]]
async ainvoke(input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any) → Output[source]¶
Default implementation of ainvoke, calls invoke from a thread.
The default implementation allows usage of async code even if
the runnable did not implement a native async version of invoke.
Subclasses should override this method if they can run asynchronously.
Parameters
input (Input) – 
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
Output
assign(**kwargs: Union[Runnable[Dict[str, Any], Any], Callable[[Dict[str, Any]], Any], Mapping[str, Union[Runnable[Dict[str, Any], Any], Callable[[Dict[str, Any]], Any]]]]) → RunnableSerializable[Any, Any]¶
Assigns new fields to the dict output of this runnable.
Returns a new runnable.
from langchain_community.llms.fake import FakeStreamingListLLM
from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import SystemMessagePromptTemplate
from langchain_core.runnables import Runnable
from operator import itemgetter
prompt = (
from langchain_core.runnables import Runnable
from operator import itemgetter
prompt = (
    SystemMessagePromptTemplate.from_template("You are a nice assistant.")
    + "{question}"
)
llm = FakeStreamingListLLM(responses=["foo-lish"])
chain: Runnable = prompt | llm | {"str": StrOutputParser()}
chain_with_assign = chain.assign(hello=itemgetter("str") | llm)
print(chain_with_assign.input_schema.schema())
# {'title': 'PromptInput', 'type': 'object', 'properties':
{'question': {'title': 'Question', 'type': 'string'}}}
print(chain_with_assign.output_schema.schema()) #
{'title': 'RunnableSequenceOutput', 'type': 'object', 'properties':
{'str': {'title': 'Str',
'type': 'string'}, 'hello': {'title': 'Hello', 'type': 'string'}}}
Parameters
kwargs (Union[Runnable[Dict[str, Any], Any], Callable[[Dict[str, Any]], Any], Mapping[str, Union[Runnable[Dict[str, Any], Any], Callable[[Dict[str, Any]], Any]]]]) – 
Return type
RunnableSerializable[Any, Any]
astream(input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any) → AsyncIterator[Output][source]¶
Default implementation of astream, which calls ainvoke.
Subclasses should override this method if they support streaming output.
Parameters
input (Input) – 
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
AsyncIterator[Output]
kwargs (Any) – 
Return type
AsyncIterator[Output]
astream_events(input: Any, config: Optional[RunnableConfig] = None, *, version: Literal['v1', 'v2'], include_names: Optional[Sequence[str]] = None, include_types: Optional[Sequence[str]] = None, include_tags: Optional[Sequence[str]] = None, exclude_names: Optional[Sequence[str]] = None, exclude_types: Optional[Sequence[str]] = None, exclude_tags: Optional[Sequence[str]] = None, **kwargs: Any) → AsyncIterator[StreamEvent]¶
[Beta] Generate a stream of events.
Use to create an iterator over StreamEvents that provide real-time information
about the progress of the runnable, including StreamEvents from intermediate
results.
A StreamEvent is a dictionary with the following schema:
event: str - Event names are of theformat: on_[runnable_type]_(start|stream|end).
name: str - The name of the runnable that generated the event.
run_id: str - randomly generated ID associated with the given execution ofthe runnable that emitted the event.
A child runnable that gets invoked as part of the execution of a
parent runnable is assigned its own unique ID.
parent_ids: List[str] - The IDs of the parent runnables thatgenerated the event. The root runnable will have an empty list.
The order of the parent IDs is from the root to the immediate parent.
Only available for v2 version of the API. The v1 version of the API
will return an empty list.
tags: Optional[List[str]] - The tags of the runnable that generatedthe event.
metadata: Optional[Dict[str, Any]] - The metadata of the runnablethat generated the event.
data: Dict[str, Any]
Below is a table that illustrates some evens that might be emitted by various
exclude_tags (Optional[Sequence[str]]) – Exclude logs with these tags.
kwargs (Any) – 
Return type
Union[AsyncIterator[RunLogPatch], AsyncIterator[RunLog]]
atransform(input: AsyncIterator[Input], config: Optional[RunnableConfig] = None, **kwargs: Any) → AsyncIterator[Output][source]¶
Default implementation of atransform, which buffers input and calls astream.
Subclasses should override this method if they can start producing output while
input is still being generated.
Parameters
input (AsyncIterator[Input]) – 
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
AsyncIterator[Output]
batch(inputs: List[Input], config: Optional[Union[RunnableConfig, List[RunnableConfig]]] = None, *, return_exceptions: bool = False, **kwargs: Optional[Any]) → List[Output]¶
Default implementation runs invoke in parallel using a thread pool executor.
The default implementation of batch works well for IO bound runnables.
Subclasses should override this method if they can batch more efficiently;
e.g., if the underlying runnable uses an API which supports a batch mode.
Parameters
inputs (List[Input]) – 
config (Optional[Union[RunnableConfig, List[RunnableConfig]]]) – 
return_exceptions (bool) – 
kwargs (Optional[Any]) – 
Return type
List[Output]
batch_as_completed(inputs: Sequence[Input], config: Optional[Union[RunnableConfig, Sequence[RunnableConfig]]] = None, *, return_exceptions: bool = False, **kwargs: Optional[Any]) → Iterator[Tuple[int, Union[Output, Exception]]]¶
Run invoke in parallel on a list of inputs,
yielding results as they complete.
Parameters
inputs (Sequence[Input]) –
Return type
Type[BaseModel]
get_graph(config: Optional[RunnableConfig] = None) → Graph¶
Return a graph representation of this runnable.
Parameters
config (Optional[RunnableConfig]) – 
Return type
Graph
get_input_schema(config: Optional[RunnableConfig] = None) → Type[BaseModel]¶
Get a pydantic model that can be used to validate input to the runnable.
Runnables that leverage the configurable_fields and configurable_alternatives
methods will have a dynamic input schema that depends on which
configuration the runnable is invoked with.
This method allows to get an input schema for a specific configuration.
Parameters
config (Optional[RunnableConfig]) – A config to use when generating the schema.
Returns
A pydantic model that can be used to validate input.
Return type
Type[BaseModel]
get_name(suffix: Optional[str] = None, *, name: Optional[str] = None) → str¶
Get the name of the runnable.
Parameters
suffix (Optional[str]) – 
name (Optional[str]) – 
Return type
str
get_output_schema(config: Optional[RunnableConfig] = None) → Type[BaseModel]¶
Get a pydantic model that can be used to validate output to the runnable.
Runnables that leverage the configurable_fields and configurable_alternatives
methods will have a dynamic output schema that depends on which
configuration the runnable is invoked with.
This method allows to get an output schema for a specific configuration.
Parameters
config (Optional[RunnableConfig]) – A config to use when generating the schema.
Returns
A pydantic model that can be used to validate output.
Return type
Type[BaseModel]
get_prompts(config: Optional[RunnableConfig] = None) → List[BasePromptTemplate]¶
Parameters
Parameters
config (Optional[RunnableConfig]) – 
Return type
List[BasePromptTemplate]
invoke(input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any) → Output[source]¶
Transform a single input into an output. Override to implement.
Parameters
input (Input) – The input to the runnable.
config (Optional[RunnableConfig]) – A config to use when invoking the runnable.
The config supports standard keys like ‘tags’, ‘metadata’ for tracing
purposes, ‘max_concurrency’ for controlling how much work to do
in parallel, and other keys. Please refer to the RunnableConfig
for more details.
kwargs (Any) – 
Returns
The output of the runnable.
Return type
Output
map() → Runnable[List[Input], List[Output]]¶
Return a new Runnable that maps a list of inputs to a list of outputs,
by calling invoke() with each input.
Example
from langchain_core.runnables import RunnableLambda
def _lambda(x: int) -> int:
    return x + 1
runnable = RunnableLambda(_lambda)
print(runnable.map().invoke([1, 2, 3])) # [2, 3, 4]
Return type
Runnable[List[Input], List[Output]]
pick(keys: Union[str, List[str]]) → RunnableSerializable[Any, Any]¶
Pick keys from the dict output of this runnable.
Pick single key:import json
from langchain_core.runnables import RunnableLambda, RunnableMap
as_str = RunnableLambda(str)
as_json = RunnableLambda(json.loads)
chain = RunnableMap(str=as_str, json=as_json)
chain.invoke("[1, 2, 3]")
def add_one(x: int) -> int:
    return x + 1
def mul_two(x: int) -> int:
    return x * 2
runnable_1 = RunnableLambda(add_one)
runnable_2 = RunnableLambda(mul_two)
sequence = runnable_1.pipe(runnable_2)
# Or equivalently:
# sequence = runnable_1 | runnable_2
# sequence = RunnableSequence(first=runnable_1, last=runnable_2)
sequence.invoke(1)
await sequence.ainvoke(1)
# -> 4
sequence.batch([1, 2, 3])
await sequence.abatch([1, 2, 3])
# -> [4, 6, 8]
Parameters
others (Union[Runnable[Any, Other], Callable[[Any], Other]]) – 
name (Optional[str]) – 
Return type
RunnableSerializable[Input, Other]
stream(input: Input, config: Optional[RunnableConfig] = None, **kwargs: Any) → Iterator[Output][source]¶
Default implementation of stream, which calls invoke.
Subclasses should override this method if they support streaming output.
Parameters
input (Input) – 
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
Iterator[Output]
transform(input: Iterator[Input], config: Optional[RunnableConfig] = None, **kwargs: Any) → Iterator[Output][source]¶
Default implementation of transform, which buffers input and then calls stream.
Subclasses should override this method if they can start producing output while
input is still being generated.
Parameters
input (Iterator[Input]) – 
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
Iterator[Output]
kwargs (Any) – 
Return type
Iterator[Output]
with_alisteners(*, on_start: Optional[AsyncListener] = None, on_end: Optional[AsyncListener] = None, on_error: Optional[AsyncListener] = None) → Runnable[Input, Output]¶
Bind asynchronous lifecycle listeners to a Runnable, returning a new Runnable.
on_start: Asynchronously called before the runnable starts running.
on_end: Asynchronously called after the runnable finishes running.
on_error: Asynchronously called if the runnable throws an error.
The Run object contains information about the run, including its id,
type, input, output, error, start_time, end_time, and any tags or metadata
added to the run.
Example:
Parameters
on_start (Optional[AsyncListener]) – 
on_end (Optional[AsyncListener]) – 
on_error (Optional[AsyncListener]) – 
Return type
Runnable[Input, Output]
with_config(config: Optional[RunnableConfig] = None, **kwargs: Any) → Runnable[Input, Output]¶
Bind config to a Runnable, returning a new Runnable.
Parameters
config (Optional[RunnableConfig]) – 
kwargs (Any) – 
Return type
Runnable[Input, Output]
with_fallbacks(fallbacks: Sequence[Runnable[Input, Output]], *, exceptions_to_handle: Tuple[Type[BaseException], ...] = (<class 'Exception'>,), exception_key: Optional[str] = None) → RunnableWithFallbacksT[Input, Output]¶
Add fallbacks to a runnable, returning a new Runnable.
Example
from typing import Iterator
from langchain_core.runnables import RunnableGenerator
def _generate_immediate_error(input: Iterator) -> Iterator[str]:
    raise ValueError()
    yield ""
def _generate(input: Iterator) -> Iterator[str]:
raise ValueError("x is 1")
    else:
         pass
runnable = RunnableLambda(_lambda)
try:
    runnable.with_retry(
        stop_after_attempt=2,
        retry_if_exception_type=(ValueError,),
    ).invoke(1)
except ValueError:
    pass
assert (count == 2)
Parameters
retry_if_exception_type (Tuple[Type[BaseException], ...]) – A tuple of exception types to retry on
wait_exponential_jitter (bool) – Whether to add jitter to the wait time
between retries
stop_after_attempt (int) – The maximum number of attempts to make before giving up
Returns
A new Runnable that retries the original runnable on exceptions.
Return type
Runnable[Input, Output]
with_types(*, input_type: Optional[Type[Input]] = None, output_type: Optional[Type[Output]] = None) → Runnable[Input, Output]¶
Bind input and output types to a Runnable, returning a new Runnable.
Parameters
input_type (Optional[Type[Input]]) – 
output_type (Optional[Type[Output]]) – 
Return type
Runnable[Input, Output]
Examples using RunnableGenerator¶
How to create a custom Output Parser