diff --git a/metagpt/actions/di/write_analysis_code.py b/metagpt/actions/di/write_analysis_code.py
index ddfbe956d..aaf4911f2 100644
--- a/metagpt/actions/di/write_analysis_code.py
+++ b/metagpt/actions/di/write_analysis_code.py
@@ -31,7 +31,7 @@ class WriteAnalysisCode(Action):
 
         rsp = await self._aask(reflection_prompt, system_msgs=[REFLECTION_SYSTEM_MSG])
         reflection = json.loads(CodeParser.parse_code(text=rsp))
-        if '```python' in reflection["improved_impl"]:
+        if "```python" in reflection["improved_impl"]:
             reflection["improved_impl"] = CodeParser.parse_code(text=reflection["improved_impl"], lang="python")
 
         return reflection["improved_impl"]