Merge pull request #5 from Li-XW707/patch-2

Update 5-2.py

Author: OctopusLian

chapter05/5-2.py

@@ -34,5 +34,5 @@
     print("in true")
 
 # 测试特定的值是否未包含在列表中
-if 'aaaai' in cars:
+if 'aaaai' not in cars:
     print("not in true")