Source code for langchain_core.runnables.utils

from __future__ import annotations

import ast
import asyncio
import inspect
import textwrap
from inspect import signature
from itertools import groupby
from typing import (
    Any,
    AsyncIterable,
    Callable,
    Coroutine,
    Dict,
    Iterable,
    List,
    Mapping,
    NamedTuple,
    Optional,
    Protocol,
    Sequence,
    Set,
    TypeVar,
    Union,
)

Input = TypeVar("Input", contravariant=True)
# Output type should implement __concat__, as eg str, list, dict do
Output = TypeVar("Output", covariant=True)


[docs]async def gated_coro(semaphore: asyncio.Semaphore, coro: Coroutine) -> Any: """Run a coroutine with a semaphore. Args: semaphore: The semaphore to use. coro: The coroutine to run. Returns: The result of the coroutine. """ async with semaphore: return await coro
[docs]async def gather_with_concurrency(n: Union[int, None], *coros: Coroutine) -> list: """Gather coroutines with a limit on the number of concurrent coroutines.""" if n is None: return await asyncio.gather(*coros) semaphore = asyncio.Semaphore(n) return await asyncio.gather(*(gated_coro(semaphore, c) for c in coros))
[docs]def accepts_run_manager(callable: Callable[..., Any]) -> bool: """Check if a callable accepts a run_manager argument.""" try: return signature(callable).parameters.get("run_manager") is not None except ValueError: return False
[docs]def accepts_config(callable: Callable[..., Any]) -> bool: """Check if a callable accepts a config argument.""" try: return signature(callable).parameters.get("config") is not None except ValueError: return False
[docs]class IsLocalDict(ast.NodeVisitor): """Check if a name is a local dict."""
[docs] def __init__(self, name: str, keys: Set[str]) -> None: self.name = name self.keys = keys
[docs] def visit_Subscript(self, node: ast.Subscript) -> Any: if ( isinstance(node.ctx, ast.Load) and isinstance(node.value, ast.Name) and node.value.id == self.name and isinstance(node.slice, ast.Constant) and isinstance(node.slice.value, str) ): # we've found a subscript access on the name we're looking for self.keys.add(node.slice.value)
[docs] def visit_Call(self, node: ast.Call) -> Any: if ( isinstance(node.func, ast.Attribute) and isinstance(node.func.value, ast.Name) and node.func.value.id == self.name and node.func.attr == "get" and len(node.args) in (1, 2) and isinstance(node.args[0], ast.Constant) and isinstance(node.args[0].value, str) ): # we've found a .get() call on the name we're looking for self.keys.add(node.args[0].value)
[docs]class IsFunctionArgDict(ast.NodeVisitor): """Check if the first argument of a function is a dict."""
[docs] def __init__(self) -> None: self.keys: Set[str] = set()
[docs] def visit_Lambda(self, node: ast.Lambda) -> Any: input_arg_name = node.args.args[0].arg IsLocalDict(input_arg_name, self.keys).visit(node.body)
[docs] def visit_FunctionDef(self, node: ast.FunctionDef) -> Any: input_arg_name = node.args.args[0].arg IsLocalDict(input_arg_name, self.keys).visit(node)
[docs] def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef) -> Any: input_arg_name = node.args.args[0].arg IsLocalDict(input_arg_name, self.keys).visit(node)
[docs]class GetLambdaSource(ast.NodeVisitor): """Get the source code of a lambda function."""
[docs] def __init__(self) -> None: """Initialize the visitor.""" self.source: Optional[str] = None self.count = 0
[docs] def visit_Lambda(self, node: ast.Lambda) -> Any: """Visit a lambda function.""" self.count += 1 if hasattr(ast, "unparse"): self.source = ast.unparse(node)
[docs]def get_function_first_arg_dict_keys(func: Callable) -> Optional[List[str]]: """Get the keys of the first argument of a function if it is a dict.""" try: code = inspect.getsource(func) tree = ast.parse(textwrap.dedent(code)) visitor = IsFunctionArgDict() visitor.visit(tree) return list(visitor.keys) if visitor.keys else None except (SyntaxError, TypeError, OSError): return None
[docs]def get_lambda_source(func: Callable) -> Optional[str]: """Get the source code of a lambda function. Args: func: a callable that can be a lambda function Returns: str: the source code of the lambda function """ try: code = inspect.getsource(func) tree = ast.parse(textwrap.dedent(code)) visitor = GetLambdaSource() visitor.visit(tree) return visitor.source if visitor.count == 1 else None except (SyntaxError, TypeError, OSError): return None
[docs]def indent_lines_after_first(text: str, prefix: str) -> str: """Indent all lines of text after the first line. Args: text: The text to indent prefix: Used to determine the number of spaces to indent Returns: str: The indented text """ n_spaces = len(prefix) spaces = " " * n_spaces lines = text.splitlines() return "\n".join([lines[0]] + [spaces + line for line in lines[1:]])
[docs]class AddableDict(Dict[str, Any]): """ Dictionary that can be added to another dictionary. """ def __add__(self, other: AddableDict) -> AddableDict: chunk = AddableDict(self) for key in other: if key not in chunk or chunk[key] is None: chunk[key] = other[key] elif other[key] is not None: try: added = chunk[key] + other[key] except TypeError: added = other[key] chunk[key] = added return chunk def __radd__(self, other: AddableDict) -> AddableDict: chunk = AddableDict(other) for key in self: if key not in chunk or chunk[key] is None: chunk[key] = self[key] elif self[key] is not None: try: added = chunk[key] + self[key] except TypeError: added = self[key] chunk[key] = added return chunk
_T_co = TypeVar("_T_co", covariant=True) _T_contra = TypeVar("_T_contra", contravariant=True)
[docs]class SupportsAdd(Protocol[_T_contra, _T_co]): """Protocol for objects that support addition.""" def __add__(self, __x: _T_contra) -> _T_co: ...
Addable = TypeVar("Addable", bound=SupportsAdd[Any, Any])
[docs]def add(addables: Iterable[Addable]) -> Optional[Addable]: """Add a sequence of addable objects together.""" final = None for chunk in addables: if final is None: final = chunk else: final = final + chunk return final
[docs]async def aadd(addables: AsyncIterable[Addable]) -> Optional[Addable]: """Asynchronously add a sequence of addable objects together.""" final = None async for chunk in addables: if final is None: final = chunk else: final = final + chunk return final
[docs]class ConfigurableField(NamedTuple): """A field that can be configured by the user.""" id: str name: Optional[str] = None description: Optional[str] = None annotation: Optional[Any] = None is_shared: bool = False def __hash__(self) -> int: return hash((self.id, self.annotation))
[docs]class ConfigurableFieldSingleOption(NamedTuple): """A field that can be configured by the user with a default value.""" id: str options: Mapping[str, Any] default: str name: Optional[str] = None description: Optional[str] = None is_shared: bool = False def __hash__(self) -> int: return hash((self.id, tuple(self.options.keys()), self.default))
[docs]class ConfigurableFieldMultiOption(NamedTuple): """A field that can be configured by the user with multiple default values.""" id: str options: Mapping[str, Any] default: Sequence[str] name: Optional[str] = None description: Optional[str] = None is_shared: bool = False def __hash__(self) -> int: return hash((self.id, tuple(self.options.keys()), tuple(self.default)))
AnyConfigurableField = Union[ ConfigurableField, ConfigurableFieldSingleOption, ConfigurableFieldMultiOption ]
[docs]class ConfigurableFieldSpec(NamedTuple): """A field that can be configured by the user. It is a specification of a field.""" id: str annotation: Any name: Optional[str] = None description: Optional[str] = None default: Any = None is_shared: bool = False dependencies: Optional[List[str]] = None
[docs]def get_unique_config_specs( specs: Iterable[ConfigurableFieldSpec], ) -> List[ConfigurableFieldSpec]: """Get the unique config specs from a sequence of config specs.""" grouped = groupby( sorted(specs, key=lambda s: (s.id, *(s.dependencies or []))), lambda s: s.id ) unique: List[ConfigurableFieldSpec] = [] for id, dupes in grouped: first = next(dupes) others = list(dupes) if len(others) == 0: unique.append(first) elif all(o == first for o in others): unique.append(first) else: raise ValueError( "RunnableSequence contains conflicting config specs" f"for {id}: {[first] + others}" ) return unique