dict
‘‘‘
#數據類型劃分：可變數據類型，不可變數據類型
不可變數據類型：元組，bool int str       可哈希
可變數據類型：list，dict set             不可哈希
dict key 必須是不可變數據類型，可哈希，
    value：任意數據類型。
dict 優點：二分查找去查詢
         存儲大量的關系型數據
      特點：無序的

‘‘‘
# dic = {
#     ‘name‘:[‘大猛‘,‘小孟‘],
#     ‘py9‘:[{‘num‘:71,‘avg_age‘:18,},
#            {‘num‘: 71, ‘avg_age‘: 18, },
 
#            {‘num‘: 71, ‘avg_age‘: 18, },
#            ],
#     True:1,
#     (1,2,3):‘wuyiyi‘,
#     2:‘二哥‘,
# }
# print(dic)
dic1 = {‘age‘: 18, ‘name‘: ‘jin‘, ‘sex‘: ‘male‘,}
#增：
# dic1[‘high‘] = 185  #沒有鍵值對，添加
# dic1[‘age‘] = 16  #如果有鍵，則值覆蓋

# dic1.setdefault(‘weight‘)  # 有鍵值對，不做任何改變，沒有才添加。
# dic1.setdefault(‘weight‘,150)
 
# dic1.setdefault(‘name‘,‘二哥‘)
# print(dic1)

#刪
# print(dic1.pop(‘age‘))   # 有返回值，按鍵去刪除
# print(dic1.pop(‘二哥‘,None))   # 可設置返回值
# print(dic1)

# print(dic1.popitem())  # 隨機刪除 有返回值 元組裏面是刪除的鍵值。
# # print(dic1)

# del dic1[‘name1‘]
# print(dic1)
# del dic1
# print(dic1)

# dic1.clear() #清空字典

#改  update
# dic1[‘age‘] = 16
 

# dic = {"name":"jin","age":18,"sex":"male"}
# dic2 = {"name":"alex","weight":75}
# dic2.update(dic)  #
#
# print(dic)
# print(dic2)
dic1 = {‘age‘: 18, ‘name‘: ‘jin‘, ‘sex‘: ‘male‘,}
#查
# print(dic1.keys(),type(dic1.keys()))
# print(dic1.values())
# print(dic1.items())

# for i in dic1:
#     print(i)
# for i in dic1.keys():
#     print(i)

# for i in dic1.values():
#     print(i)

# a,b = 1,2
# print(a,b)

# a = 1
# b = 2
# a,b = b,a
# print(a,b)
# a,b = [1,2],[2,3]
# a,b = (1,2)
# print(a,b)

# for k,v in dic1.items():
#     print(k,v)

# v1 = dic1[‘name‘]
# print(v1)

# v2 = dic1[‘name1‘]  # 報錯
# print(v2)

# print(dic1.get(‘name1‘,‘沒有這個鍵‘))

python學習筆記之字典