File size: 2,948 Bytes
b69a231 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 | from __future__ import annotations
from dataclasses import dataclass
from typing import List, Optional
from langchain_core.tools import tool
from langchain_community.utilities import WikipediaAPIWrapper
from langchain_community.tools import DuckDuckGoSearchRun, WikipediaQueryRun, ArxivQueryRun
# --- Calculator tool (safe arithmetic) ---
import ast
import operator as op
_ALLOWED_OPS = {
ast.Add: op.add,
ast.Sub: op.sub,
ast.Mult: op.mul,
ast.Div: op.truediv,
ast.Pow: op.pow,
ast.USub: op.neg,
ast.Mod: op.mod,
ast.FloorDiv: op.floordiv,
}
def _eval_expr(expr: str) -> float:
"""Safely evaluate a basic arithmetic expression."""
node = ast.parse(expr, mode="eval").body
def _eval(n):
if isinstance(n, ast.Num): # py<3.8
return n.n
if isinstance(n, ast.Constant): # py>=3.8
if isinstance(n.value, (int, float)):
return n.value
raise ValueError("Only numbers are allowed.")
if isinstance(n, ast.BinOp) and type(n.op) in _ALLOWED_OPS:
return _ALLOWED_OPS[type(n.op)](_eval(n.left), _eval(n.right))
if isinstance(n, ast.UnaryOp) and type(n.op) in _ALLOWED_OPS:
return _ALLOWED_OPS[type(n.op)](_eval(n.operand))
raise ValueError("Only basic arithmetic is allowed.")
return float(_eval(node))
@tool
def calculator(expression: str) -> str:
"""Evaluate a math expression. Input must be a plain arithmetic expression (e.g., '12*(3+4)')."""
try:
return str(_eval_expr(expression))
except Exception as e:
return f"[calculator error] {e}"
# --- Web/Wiki/Arxiv tools ---
def make_web_wiki_arxiv_tools(*, wiki_k: int = 3, wiki_chars: int = 2000):
"""Return tool objects compatible with LangGraph ToolNode."""
web = DuckDuckGoSearchRun()
# IMPORTANT: WikipediaQueryRun requires api_wrapper in your installed versions.
wiki_wrapper = WikipediaAPIWrapper(top_k_results=wiki_k, doc_content_chars_max=wiki_chars)
wiki = WikipediaQueryRun(api_wrapper=wiki_wrapper)
# ArxivQueryRun works similarly; its underlying API doesn't require keys.
arxiv = ArxivQueryRun()
return [web, wiki, arxiv, calculator]
# @dataclass
# class ToolResult:
# tool: str
# output: str
@dataclass
class ToolResult:
tool: str
output: str
ok: bool = True
error: Optional[str] = None
def run_tools_once(query: str, *, wiki_k: int = 3, wiki_chars: int = 2000) -> List[ToolResult]:
"""Non-agent helper: run each tool once and return outputs (good for debugging)."""
tools = make_web_wiki_arxiv_tools(wiki_k=wiki_k, wiki_chars=wiki_chars)
out: List[ToolResult] = []
for t in tools:
try:
out.append(ToolResult(tool=t.name, output=str(t.run(query))))
except Exception as e:
out.append(ToolResult(tool=t.name, output=f"[tool error] {e}", ok=False, error=str(e)))
return out
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