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langchain/langchain/agents/tools.py

82 lines
2.8 KiB
Python

"""Interface for tools."""
import asyncio
from dataclasses import dataclass
from inspect import signature
from typing import Any, Awaitable, Callable, Optional, Union
@dataclass
class Tool:
"""Interface for tools."""
name: str
func: Callable[[str], str]
description: Optional[str] = None
return_direct: bool = False
# If the tool has a coroutine, then we can use this to run it asynchronously
coroutine: Optional[Callable[[str], Awaitable[str]]] = None
def __call__(self, *args: Any, **kwargs: Any) -> str:
"""Make tools callable by piping through to `func`."""
if asyncio.iscoroutinefunction(self.func):
raise TypeError("Coroutine cannot be called directly")
return self.func(*args, **kwargs)
def tool(
*args: Union[str, Callable], return_direct: bool = False
) -> Union[Callable, Tool]:
"""Make tools out of functions, can be used with or without arguments.
Requires:
- Function must be of type (str) -> str
- Function must have a docstring
Examples:
.. code-block:: python
@tool
def search_api(query: str) -> str:
# Searches the API for the query.
return
@tool("search", return_direct=True)
def search_api(query: str) -> str:
# Searches the API for the query.
return
"""
def _make_with_name(tool_name: str) -> Callable:
def _make_tool(func: Callable[[str], str]) -> Tool:
assert func.__doc__, "Function must have a docstring"
# Description example:
# search_api(query: str) - Searches the API for the query.
description = f"{tool_name}{signature(func)} - {func.__doc__.strip()}"
tool = Tool(
name=tool_name,
func=func,
description=description,
return_direct=return_direct,
)
return tool
return _make_tool
if len(args) == 1 and isinstance(args[0], str):
# if the argument is a string, then we use the string as the tool name
# Example usage: @tool("search", return_direct=True)
return _make_with_name(args[0])
elif len(args) == 1 and callable(args[0]):
# if the argument is a function, then we use the function name as the tool name
# Example usage: @tool
return _make_with_name(args[0].__name__)(args[0])
elif len(args) == 0:
# if there are no arguments, then we use the function name as the tool name
# Example usage: @tool(return_direct=True)
def _partial(func: Callable[[str], str]) -> Tool:
return _make_with_name(func.__name__)(func)
return _partial
else:
raise ValueError("Too many arguments for tool decorator")