def check_index(index):
  if index < 5:
    raise IndexError('index must greater than 10')
 
 
class S_List:
  def __init__(self):
    self.ll = [None] * 10
 
  def __len__(self): # 提取參數(shù)長度
    return len(self.ll)
 
  def __getitem__(self, index): # 取出參數(shù)
    return self.ll[index]
 
  def __setitem__(self, index, value): # 設置參數(shù)
    check_index(index)
    self.ll[index] = value
 
  def __delitem__(self, index):
    check_index(index)
    self.ll.pop(index)
 
  def __str__(self): # 打印對象時，輸出列表本身
    return str(self.ll)
 
  def __del__(self): # 沒有手工刪除在程序結束時釋放
    print('我被釋放了!')
 
sl = S_List()
del sl[3]
 
print(isinstance(sl, S_List))
print(f'輸出原始數(shù)據(jù):{sl}')
sl[6] = 'six'
print(f'修改后原始數(shù)據(jù):{sl}')
print(f'隨便取一個值:{sl[1]}')
del sl[6]
print(f'第二次修改后原始數(shù)據(jù):{sl}')
del sl[3]
# sl[4] = 'oh'
print(sl)

True
輸出原始數(shù)據(jù):[None, None, None, None, None, None, None, None, None, None]
修改后原始數(shù)據(jù):[None, None, None, None, None, None, 'six', None, None, None]
隨便取一個值:None
第二次修改后原始數(shù)據(jù):[None, None, None, None, None, None, None, None, None]
[None, None, None, None, None, None, None, None, None]
我被釋放了!

Traceback (most recent call last):
 File "/Users/shijianzhong/Desktop/yunzuan_buy/study_base.py", line 81, in <module>
  del sl[3]
 File "/Users/shijianzhong/Desktop/yunzuan_buy/study_base.py", line 73, in __delitem__
  check_index(index)
 File "/Users/shijianzhong/Desktop/yunzuan_buy/study_base.py", line 53, in check_index
  raise IndexError('index must greater than 10')
IndexError: index must greater than 10
我被釋放了!

class Ii:
  def __getitem__(self, item):
    return self.__dict__[item]
  def __setitem__(self, key, value):
    self.__dict__[key] = value
 
li = Ii()
li[3] = 5
print(li[3])
 
# 5

def check_str(params):
  if not isinstance(params, str):
    raise ValueError('parameters must is string')
   
def check_index(index):
  if index < 5:
    raise IndexError('index must greater than 10')
 
class Super_List(list):
  def __init__(self):
    super(Super_List, self).__init__()   # 調(diào)用父類初始化
    self += [None] * 5           # 對初始化的參數(shù)進行修改
 
  def append(self, *args):          # 對append進行參數(shù)限制
    for i in args:
      check_str(i)
    return super(Super_List, self).append(*args)
 
  def insert(self, index, *args):       # 對insert的參數(shù)（索引及插入元素）進行限制
    check_index(index) # 判斷插入位置
    for i in args:
      check_str(i)
    return super(Super_List, self).insert(index, *args)
 
  def extend(self, *args):          # 對擴張的列表元素進行判斷
    temp = args[0]
    for i in temp:
      check_str(i)
    super(Super_List, self).extend(*args)
   
  def __delitem__(self, index):        # 對del命令的索引進行判斷
    check_index(index)
    super(Super_List, self).__delitem__(index)
 
  def clear(self):              # 禁止使用clear命令
    raise TypeError('No permission')
 
ss_l = Super_List()
print(ss_l)
ss_l.append('1')
ss_l.insert(5, 'a')
ss_l.extend(['a', 'b', 'c'])
ss_l.clear()
print(ss_l)

class Dict(dict):
  def __init__(self, *args, **kwargs):
    # self.x = 12
    super(Dict, self).__init__(*args, **kwargs)
 
  def __missing__(self, key):
    self[key] = None
    return self[key]
l = Dict(((1,2),(2,3)))
print(l)
print(l[8])
print(l)

{1: 2, 2: 3}
None
{1: 2, 2: 3, 8: None}

# -*- coding: utf-8 -*-

class Dict(dict):
  def __init__(self, *args, **kwargs):
    super(Dict, self).__init__(*args, **kwargs)

  def __missing__(self, item):
    # 判斷進來的參數(shù)是不是字符串，如果是字符串說明就是對象主動調(diào)用__missing__進來的
    # 非__getitem__導入的
    if isinstance(item, str):
      self[item] = 'Default Empty'
      return self[item]
    # 如果對象非字符串，明顯說明是__getitem__導入的，判斷長度就可以
    else:
      key, value = item
      self[key] = value   # 自身進行賦值
      return self[key]   # 返回value


  def __getitem__(self, item):
    if not isinstance(item, tuple):  # 傳進來的item進行判斷，如果非元祖，直接調(diào)用父類綁定self方法返回
      return super(Dict, self).__getitem__(item)
    elif len(item) == 2 and isinstance(item, tuple):  # 如果是元祖，又是2位長度的，進行賦值。其實感覺元祖判斷沒有好像也沒關系
      k, _ = item
      if k in self:
        return super(Dict, self).__getitem__(k)   # 如果k在self里面繼續(xù)調(diào)用父類綁定self方法返回
      else:
        res = self.__missing__(item)       # 否則調(diào)用自身的__missing
        return res
    else:
      raise TypeError('input pattern error')     # 元素數(shù)量超過2個，直接報錯

l = Dict((('name','sidian'),('age',99)))

print(l)
print(l['name','wudian'])
print(l['addr','杭州'])
print(l['hobby'])
print(l)

{'name': 'sidian', 'age': 99}
sidian
杭州
Default Empty
{'name': 'sidian', 'age': 99, 'addr': '杭州', 'hobby': 'Default Empty'}