From 620088be2fdfcb22b390eb984851d7755738a27d Mon Sep 17 00:00:00 2001
From: Cocoon-Break <54054995+kuishou68@users.noreply.github.com>
Date: Fri, 24 Apr 2026 19:09:44 +0800
Subject: [PATCH] fix: check isinstance before len in VariableAssigner
 _remove_first/_remove_last (#14281)

fix: check isinstance before len in VariableAssigner _remove_first/_remove_last
---
 agent/component/variable_assigner.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/agent/component/variable_assigner.py b/agent/component/variable_assigner.py
index 08b2833431..dd6182c7ce 100644
--- a/agent/component/variable_assigner.py
+++ b/agent/component/variable_assigner.py
@@ -141,20 +141,18 @@ class VariableAssigner(ComponentBase,ABC):
             return variable + parameter
 
     def _remove_first(self,variable):
-        if len(variable)==0:
-            return variable
         if not isinstance(variable,list):
             return "ERROR:VARIABLE_NOT_LIST"
-        else:
-            return variable[1:]
+        if len(variable)==0:
+            return variable
+        return variable[1:]
 
     def _remove_last(self,variable):
-        if len(variable)==0:
-            return variable
         if not isinstance(variable,list):
             return "ERROR:VARIABLE_NOT_LIST"
-        else:
-            return variable[:-1]
+        if len(variable)==0:
+            return variable
+        return variable[:-1]
 
     def is_number(self, value):
         if isinstance(value, bool):