feat: avoid expensive str() calls in enforce_ex when logging is disabled (#421)

Author: Copilot

casbin/core_enforcer.py

@@ -508,17 +508,18 @@ def enforce_ex(self, *rvals):
         result = effect_to_bool(final_effect)
 
         # Log request.
-
-        req_str = "Request: "
-        req_str = req_str + ", ".join([str(v) for v in rvals])
-
-        req_str = req_str + " ---> %s" % result
-        if result:
-            self.logger.info(req_str)
-        else:
-            # leaving this in warning for now, if it's very noise this can be changed to info or debug,
-            # or change the log level
-            self.logger.warning(req_str)
+        if (result and self.logger.isEnabledFor(logging.INFO)) or (
+            not result and self.logger.isEnabledFor(logging.WARNING)
+        ):
+            req_str = "Request: "
+            req_str = req_str + ", ".join([str(v) for v in rvals])
+            req_str = req_str + " ---> %s" % result
+            if result:
+                self.logger.info(req_str)
+            else:
+                # leaving this in warning for now, if it's very noise this can be changed to info or debug,
+                # or change the log level
+                self.logger.warning(req_str)
 
         explain_rule = []
         if explain_index != -1 and explain_index < policy_len: