Python9-字典-day5

数据类型划分：可变数据类型，不可变数据类型
不可变数据类型：元祖 bool  int str 可哈希
可变数据类型：list，dic set       不可哈希
dict key 必须是不可变数据类型，可哈希
      value:任何数据类型
dict优点：二分查找去查询
          存储大量的关系型数据
    特点：无序的，无索引
增

dic1={'age': 18, 'name': 'jin', 'sex': 'male', 'k': 'v'}
#增
dic1['high'] = 185 #没有键值对，添加
print(dic1)
dic1['age'] = 16   #存在键值对，则覆盖
print(dic1)
dic1.setdefault('weight',150)  #有键值对，不做任何改变，没有才增加

print(dic1)

{'high': 185, 'sex': 'male', 'k': 'v', 'age': 18, 'name': 'jin'}
{'high': 185, 'sex': 'male', 'k': 'v', 'age': 16, 'name': 'jin'}
{'sex': 'male', 'k': 'v', 'weight': 150, 'high': 185, 'age': 16, 'name': 'jin'}

删除

dic1.pop('age') #有返回值
print(dic1)
print(dic1.pop('six',None)) #可设置返回值
print(dic1)

dic1.popitem()  #随机删除，有返回值。元祖里是删除键值
print(dic1)
dic1.clear()  #清空字典
print(dic1)
del dic1['name']
print(dic1)

{'name': 'jin', 'sex': 'male', 'k': 'v'}
None
{'name': 'jin', 'sex': 'male', 'k': 'v'}
{'sex': 'male', 'k': 'v'}
{}
{'age': 18, 'sex': 'male', 'k': 'v'}

改

dic1['age']=16
print(dic1)
dic = {"name":"jin","age":18,"sex":"male"}
dic2 = {"name":"alex","weight":75}
dic2.update(dic)  # 将dic所有的键值对覆盖添加（相同的覆盖，没有的添加）到dic2中
print(dic)
print(dic2)

{'name': 'jin', 'age': 16, 'k': 'v', 'sex': 'male'}
{'name': 'jin', 'age': 18, 'sex': 'male'}
{'weight': 75, 'name': 'jin', 'age': 18, 'sex': 'male'}

查

dic1={'age': 18, 'name': 'jin', 'sex': 'male', 'k': 'v'}
print(dic1.keys(),type(dic1.keys()))
print(dic1.values())
print(dic1.items())

dict_keys(['age', 'sex', 'k', 'name']) <class 'dict_keys'>
dict_values([18, 'male', 'v', 'jin'])
dict_items([('age', 18), ('sex', 'male'), ('k', 'v'), ('name', 'jin')])

print(dic1.get('name1'，‘no this key’))  #不会报错
no this key

字典循环
for i in dic1:
    print(i)
name
k
age
sex

for i in dic1.keys():
    print(i)
name
k
age
sex

for i in dic1.items():
    print(i)
('name', 'jin')
('k', 'v')
('age', 18)
('sex', 'male')

for i in dic1.values():
    print(i)
jin
v
18
male

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

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

name jin
k v
age 18
sex male

嵌套

dic = {
    'name':['alex','wusir','taibai'],
    'py9' :{
        'time':'',
        'learn_money':19800,
        'addr':'CBD',
    },
    'age':21
}

dic['age']=56
print(dic['name'])
dic['name'].append('ritian')
print(dic)
dic['name'][1] = dic['name'][1].upper()
print(dic)

l = [1,2,'wusi']
l[2]=l[2].upper()
print(l)

dic['py9'] ['femail']=6
print(dic)

{'name': ['alex', 'wusir', 'taibai', 'ritian'], 'age': 56, 'py9': {'learn_money': 19800, 'time': '', 'addr': 'CBD'}}
{'name': ['alex', 'WUSIR', 'taibai', 'ritian'], 'age': 56, 'py9': {'learn_money': 19800, 'time': '', 'addr': 'CBD'}}
[1, 2, 'WUSI']
{'name': ['alex', 'WUSIR', 'taibai', 'ritian'], 'age': 56, 'py9': {'learn_money': 19800, 'time': '', 'addr': 'CBD', 'femail': 6}}

info =input('>>>')
for i in info:
    if i.isalpha():
        info = info.replace(i," ")
l = info.split()
print(len(l))

>>>123ab123
2