python 列表操作 为什么两个列表存在相同的数据 用 if i in x: 会报不存在呢. if i not in x: 有一样存在说成不存在

Question

问题遇到的现象和发生背景

> d:\python\pythonapplication1\20220420\write.py(42)write()
-> if dxr in xlsj:
(Pdb) n
> d:\python\pythonapplication1\20220420\write.py(53)write()
-> if dxr not in xlsj:
(Pdb) n
> d:\python\pythonapplication1\20220420\write.py(54)write()
-> print("数据不存在重复")
(Pdb) dxr
[['03/01/2016', 'BJ', 8, 5]]
(Pdb) xlsj
[['03/01/2016', 'BJ', 8, 5], ['17/01/2016', 'BJ', 12, 2], ['31/01/2016', 'BJ', 19, 2], ['14/02/2016', 'BJ', -3, 3]]

while True:
      xlsj = [['03/01/2016', 'BJ', 8, 5], ['17/01/2016', 'BJ', 12, 2], ['31/01/2016', 'BJ', 19, 2], ['14/02/2016', 'BJ', -3, 3], ['28/02/2016', 'BJ', 19, 2], ['13/03/2016', 'BJ', 5, 3]]
      dxr = []
      a1 = input("日期:")
      a2 = input("城市:")
      a3 = int(input("数据1:"))
      a4 = int(input("数据2:"))
      dxr.append([a1, a2, a3, a4])
      if dxr not in xlsj:
            print("数据不存在重复")

问题
1.为什么我这样错了,我要怎么样写才能判断两个数量不相同的列表里面的数据是不是有重复?

Answer 1

两个问题：
1、dxr不知道是否在外部定义，如果没有定义，则改为 dxr = [a1, a2, a3, a4]
2、xlsj重复赋值了，第二次赋了个空值

while True:
      xlsj = [['03/01/2016', 'BJ', 8, 5], ['17/01/2016', 'BJ', 12, 2], ['31/01/2016', 'BJ', 19, 2], ['14/02/2016', 'BJ', -3, 3], ['28/02/2016', 'BJ', 19, 2], ['13/03/2016', 'BJ', 5, 3]]
      a1 = input("日期:")
      a2 = input("城市:")
      a3 = int(input("数据1:"))
      a4 = int(input("数据2:"))
      dxr = [a1, a2, a3, a4]
      if dxr not in xlsj:
            print("数据不存在重复")