61 lines
2.7 KiB
Python
61 lines
2.7 KiB
Python
# ════════════════════════════════════════════════════════════════
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# tools/calculator.py
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# ════════════════════════════════════════════════════════════════
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"""安全的数学表达式计算工具（AST 解析，防注入）"""
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import ast
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import operator
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from config.settings import settings
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from tools.base_tool import BaseTool, ToolResult
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class CalculatorTool(BaseTool):
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name = "calculator"
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description = "计算数学表达式，支持加减乘除、幂运算、括号等"
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parameters = {
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"expression": {"type": "string", "description": "数学表达式，例如 '(1+2)*3'"},
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}
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_OPERATORS = {
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ast.Add: operator.add, ast.Sub: operator.sub,
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ast.Mult: operator.mul, ast.Div: operator.truediv,
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ast.Pow: operator.pow, ast.Mod: operator.mod,
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ast.USub: operator.neg,
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}
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def __init__(self):
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super().__init__()
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# 从配置读取精度
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self._precision = settings.tools.calculator.precision
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self.logger.debug(f"⚙️ Calculator 精度: {self._precision}")
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def execute(self, expression: str, **_) -> ToolResult:
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try:
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tree = ast.parse(expression, mode="eval")
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result = self._eval_node(tree.body)
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result = round(result, self._precision)
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return ToolResult(
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success=True,
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output=f"{expression} = {result}",
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metadata={"expression": expression, "result": result},
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)
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except (ValueError, TypeError, ZeroDivisionError) as exc:
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return ToolResult(success=False, output=f"计算错误: {exc}")
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def _eval_node(self, node: ast.AST) -> float:
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match node:
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case ast.Constant(value=v) if isinstance(v, (int, float)):
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return v
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case ast.BinOp(left=left, op=op, right=right):
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fn = self._OPERATORS.get(type(op))
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if fn is None:
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raise ValueError(f"不支持的运算符: {type(op).__name__}")
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return fn(self._eval_node(left), self._eval_node(right))
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case ast.UnaryOp(op=op, operand=operand):
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fn = self._OPERATORS.get(type(op))
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if fn is None:
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raise ValueError(f"不支持的一元运算符: {type(op).__name__}")
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return fn(self._eval_node(operand))
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case _:
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raise ValueError(f"不支持的节点: {type(node).__name__}") |