Update app.py

app.py

@@ -46,18 +46,15 @@ def brave_search_context(query, count=3):
         return ""
 
 ### CALCULATOR TOOL
+import builtins
+
 def evaluate_expression(expr) -> str:
     """
     Evaluate a simple algebraic expression string safely.
     Supports +, -, *, /, **, and parentheses.
     Retries evaluation after stripping non-numeric/non-operator characters if needed.
     """
-
-    allowed_names = {
-        k: v for k, v in vars(__builtins__).items()
-        if k in ("abs", "round")
-    }
-
+    allowed_names = {k: getattr(builtins, k) for k in ("abs", "round")}
     allowed_names.update({k: getattr(math, k) for k in ("sqrt", "pow")})
 
     def safe_eval(expression):