字典的操作（增删改查）

#_author:star#date:2019/10/26# 字典# 不可变类型：整形，字符串，元组# 可变类型：字典，列表#字典两个特点：无序，键唯一a=10print(id(a))#1351629200b=aprint(id(b))#1351629200b=15print(id(b))#1351629280print(a,b)# 10 15#字典的创建方式一dic={‘name‘:‘star‘,2:‘girl‘,‘age‘:22,‘hobby‘:{‘girl_name‘:‘angle‘,‘age‘:22,‘sex‘:‘female‘},‘sex‘:‘male‘}print(dic)# {‘name‘: ‘star‘, 2: ‘girl‘, ‘age‘: 22, ‘hobby‘: {‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}, ‘sex‘: ‘male‘}print(dic[‘hobby‘])#{‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}

#字典的创建方式二c=dict([("name","star"),])print(c)#{‘name‘: ‘star‘}d=dict(((‘age‘,36),))#注意，如果内部全部是（），记得加逗号print(d)#{‘age‘: 36}

#字典的操作：1.增dic={‘name‘:‘tong‘,‘age‘:22}dic[‘hobby‘]=‘girl‘print(dic)#{‘name‘: ‘tong‘, ‘age‘: 22, ‘hobby‘: ‘girl‘}dic.setdefault(‘age‘,23)tr=dic.setdefault(‘age‘,23)#setdefault是有返回值的，返回值是（键存在，不改动，返回字典中相应的键对应的值）print(tr)#22print(dic)# {‘name‘: ‘tong‘, ‘age‘: 22, ‘hobby‘: ‘girl‘}dic.setdefault(‘interest‘,‘coding‘)tr1=dic.setdefault(‘interest‘,‘coding‘)#键不存在，在字典中增加新的键值对，并返回相应的值print(tr1)#codingprint(dic)# {‘name‘: ‘tong‘, ‘age‘: 22, ‘hobby‘: ‘girl‘, ‘interest‘: ‘coding‘}#2.查---通过键去查找dic2={‘name‘:‘star‘,2:‘girl‘,‘age‘:22,‘hobby‘:{‘girl_name‘:‘angle‘,‘age‘:22,‘sex‘:‘female‘},‘sex‘:‘male‘}print(dic2[‘age‘])#22print(dic2.keys())#dict_keys([‘name‘, 2, ‘age‘, ‘hobby‘, ‘sex‘])print(type(dic2.keys()))#<class ‘dict_keys‘>#想要拿到一个列表，转换print(list(dic2.keys()))#[‘name‘, 2, ‘age‘, ‘hobby‘, ‘sex‘]print(dic2.values())#dict_values([‘star‘, ‘girl‘, 22, {‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}, ‘male‘])print(list(dic2.values()))#[‘star‘, ‘girl‘, 22, {‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}, ‘male‘]print(dic2.items())#dict_items([(‘name‘, ‘star‘), (2, ‘girl‘), (‘age‘, 22), (‘hobby‘, {‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}), (‘sex‘, ‘male‘)])print(list(dic2.items()))#[(‘name‘, ‘star‘), (2, ‘girl‘), (‘age‘, 22), (‘hobby‘, {‘girl_name‘: ‘angle‘, ‘age‘: 22, ‘sex‘: ‘female‘}), (‘sex‘, ‘male‘)]#3.修改dic3={‘name‘:‘star‘,2:‘girl‘,‘age‘:22,‘sex‘:‘male‘}dic3[‘name‘]=‘xing‘print(dic3)#{‘name‘: ‘xing‘, 2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘}dic4={1:‘111‘,‘lover‘:‘cake‘}dic3.update(dic4)print(dic3)#{‘name‘: ‘xing‘, 2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘, 1: ‘111‘, ‘lover‘: ‘cake‘}dic5={‘name‘:‘lai‘}#将原来的值替换dic3.update(dic5)print(dic3)#{‘name‘: ‘lai‘, 2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘, 1: ‘111‘, ‘lover‘: ‘cake‘}#4.删dic6={‘name‘:‘star‘,2:‘girl‘,‘age‘:22,‘sex‘:‘male‘}del dic6[‘name‘]#删除字典中指定键值对print(dic6)#{2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘}re=dic6.pop(‘sex‘)#删除字典中指定键值对，并返回该键对应的值print(re)print(dic6)#{2: ‘girl‘, ‘age‘: 22}dic6.clear()print(dic6)#{}dic7={‘name1‘:‘star1‘,21:‘girl1‘,‘age1‘:221,‘sex1‘:‘male1‘}re1=dic7.popitem() #随机删除某组键值对print(re1)#(‘sex1‘, ‘male1‘) 并以元组方式返回值print(dic7)#{‘name1‘: ‘star1‘, 21: ‘girl1‘, ‘age1‘: 221}del dic7#删除整个字典#print(dic7)因为字典已经不存在，所以输出报错#5.其他操作以及涉及到的方法#(5-----1)创建字典的第三种方式dic8=dic.fromkeys([‘so1‘,‘so2‘,‘so3‘],‘star‘)print(dic8)#{‘so1‘: ‘star‘, ‘so2‘: ‘star‘, ‘so3‘: ‘star‘}dic8[‘so2‘]=‘ooo‘print(dic8)#{‘so1‘: ‘star‘, ‘so2‘: ‘ooo‘, ‘so3‘: ‘star‘}dic9=dic.fromkeys([‘so1‘,‘so2‘,‘so3‘],[‘star1‘,‘star2‘])print(dic9)#{‘so1‘: [‘star1‘, ‘star2‘], ‘so2‘: [‘star1‘, ‘star2‘], ‘so3‘: [‘star1‘, ‘star2‘]}dic9[‘so2‘][1]=‘star3‘print(dic9)#{‘so1‘: [‘star1‘, ‘star3‘], ‘so2‘: [‘star1‘, ‘star3‘], ‘so3‘: [‘star1‘, ‘star3‘]}dic10={‘name‘:‘star‘,2:‘girl‘,‘age‘:22,‘sex‘:‘male‘}#(copy()r=dic10.copy()print(r)#{‘name‘: ‘star‘, 2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘}print(dic10)#{‘name‘: ‘star‘, 2: ‘girl‘, ‘age‘: 22, ‘sex‘: ‘male‘}#(5----2)字典嵌套

inf={    ‘asia‘:{‘japon‘:‘height_produce‘,‘chinese‘:‘hand_produce‘,‘singrapo‘:[‘jenry‘,‘port‘]},    ‘america‘:{‘England‘:‘car‘,‘US‘:‘big_car‘,‘gard_man‘:[‘handsome‘,‘kindness‘,‘great‘]},}print(inf[‘asia‘][‘singrapo‘][1])#portprint(inf[‘america‘][‘gard_man‘][2])#great

#（5---3）字典排序s1={2:‘222‘,6:‘666‘,0:‘000‘}print(sorted(s1))#[0, 2, 6]print(sorted(s1.values()))#[‘000‘, ‘222‘, ‘666‘]print(sorted(s1.items()))#[(0, ‘000‘), (2, ‘222‘), (6, ‘666‘)]#(  5--4)  字典的遍历

# for j in s2:#     print(j)#按照键打印name            #          ages2={‘name‘:‘star‘,‘age‘:22}for i in s2:    print(i,s2.get(i))    # name  age    # star  22

s3 = {‘name‘: ‘star‘, ‘age‘: 22}for i in s3:    print(i, s3[i])    # name  age    # star  22

for i,v in enumerate(s3.items(),1):    print(i,v)# 1 (‘name‘, ‘star‘)# 2 (‘age‘, 22)for i,v in s3.items():    print(i,v)    # name star    # age 22

原文地址：https://www.cnblogs.com/startl/p/11742518.html