• 字典是另一種可變容器模型，且可存儲任意類型對象。

• 字典的每個鍵值 key=>value 對用冒號 : 分割，每個鍵值對之間用逗號 , 分割，整個字典包括在花括號 {} 中 ,格式如下所示：

  
  

  d = {key1 : value1, key2 : value2

  
  

• 鍵必須是唯一的，但值則不必。

• 值可以取任何數據類型，但鍵必須是不可變的，如字符串，數字或元組。

  
  

• dic = {'name':'jin','age':18,'sex':'male'}
  print(dic)#{'name': 'jin', 'sex': 'male', 'age': 18}

  ####增####

• #增
  ##第一種:有則覆蓋，無則添加
  # dic = {'name':'jin','age':18,'sex':'male'}
  # dic['hobby'] = 'girl'
  # print(dic)
  #輸出{'age': 18, 'hobby': 'girl', 'sex': 'male', 'name': 'jin'}
  # dic['name'] = 'wusir'
  # print(dic)
  #{'age': 18, 'sex': 'male', 'name': 'wusir'}
  #
  ##第二種:serdefult 無則添加,有則不變
  dic = {'name':'jin','age':18,'sex':'male'}
  
  # dic.setdefault('hobby')
  # print(dic)#{'sex': 'male', 'hobby': None, 'age': 18, 'name': 'jin'}
  #'hobby'是鍵，而不是值，所以字典裏會出現'hobby':None
  
  # dic.setdefault('hobby','girl')
  # print(dic)#{'name': 'jin', 'hobby': 'girl', 'age': 18, 'sex': 'male'}
  #鍵值對 'hobby':girl添加到字典了、原字典沒有hobby
  
  # dic.setdefault('name','ritian')
  # print(dic)#{'age': 18, 'name': 'jin', 'sex': 'male'}
  #原字典中有k,name'所以不變

  ###刪####

  
  

• #pop  有返回值
  # dic = {'name':'jin','age':18,'sex':'male'}
  # print(dic.pop('age'))##返回所刪除鍵值對的age值18
  # print(dic)
  # dic.pop('hobby')##報錯
  # print(dic.pop('hobby',None))##設定返回的鍵值，當hobby不存在時，返回None
  
  
  ##clear 清空
  # dic = {'name':'jin','age':18,'sex':'male'}
  # dic.clear()
  # print(dic)#{}清空字典裏面所有鍵值對
  
  ##del
  # dic = {'name':'jin','age':18,'sex':'male'}
  # del dic
  # print(dic)#NameError: name 'dic' is not defined,通過del dic,已刪除字典dic
  
  # dic = {'name':'jin','age':18,'sex':'male'}
  # del dic['name']
  # print(dic)#{'age': 18, 'sex': 'male'},刪除dic裏面‘name’的鍵值對
  
  # dic = {'name':'jin','age':18,'sex':'male'}
  # print(dic.popitem())
  # print(dic)#每次隨機刪除dic裏面的鍵值對

  ####改#####

  
  

• # dic = {"name":"jin","age":18,"sex":"male"}
  # dic['name'] = '太白'
  # print(dic)#{'name': '太白', 'sex': 'male', 'age': 18}更改鍵name的值
  
  # 兩個字典的改
  # dic = {"name":"jin","age":18,"sex":"male"}
  # dic2 = {"name":"alex","weight":75}
  # dic2.update(dic)#將dic鍵值對，覆蓋並添加到dic2
  # print(dic)#{'age': 18, 'name': 'jin', 'sex': 'male'}
  # print(dic2)#{'age': 18, 'sex': 'male', 'name': 'jin', 'weight': 75}

  ####查####

# dic = {"name":"jin","age":18,"sex":"male"}

# print(dic['name'])#jin 查鍵所對應的值jin
# print(dic['name1'])#KeyError: 'name1'如果查看沒有的鍵，則會顯示錯誤信息
# print(dic.get('name'))#jin
# print(dic.get('name1'))#沒有此鍵時默認返回None
# print(dic.get('name1','無此鍵值對'))#無此鍵值對,後面可以設置···

##其它方法
#key() values()  item()
dic = {"name":"jin","age":18,"sex":"male"}
# print(dic.keys(),type(dic.keys()))#查看dic的鍵keys
# print(dic.keys())#
# for i in dic.keys():
#     print(i)
#列出dic的所有鍵
# for i in dic:
#     print(i)

# li = list(dic.keys())#以列表的形式查看dic鍵
# print(li)
# print(dic.values())#值

# for i in dic.values():#列出dic的鍵值
#     print(i)
#
#items 隨機打出dic的鍵值對

# print(dic.items())#打出dic的鍵值對，順序隨機
#dict_items([('age', 18), ('sex', 'male'), ('name', 'jin')])

# for i in dic.items():#
#         print(i,type(i))
# ('name', 'jin') <class 'tuple'>
# ('sex', 'male') <class 'tuple'>
# ('age', 18) <class 'tuple'>

Python3.5 字典(Dictionary)