字典常用操作:
存/取
info_dic={'name':'egon','age':18,'sex':'male'}
print(info_dic['name11111111'])
print(info_dic.get('name',None))
pop:key存在则弹出值,不存在则返回默认值,如果没有默认值则报错
print(info_dic.pop('nam123123123123123123e',None))
print(info_dic)
print(info_dic.popitem())
print(info_dic)
info_dic['level']=10
print(info_dic)
删除
info_dic={'name':'egon','age':18,'sex':'male'}
info_dic.pop()
info_dic.popitem()
del info_dic['name']
键s,值s,键值对
info_dic={'name':'egon','age':18,'sex':'male'}
print(info_dic.keys())
print(info_dic.values())
print(info_dic.items())
for k in info_dic:
print(k,info_dic[k])
print(k)
print('===>')
for k in info_dic.keys():
print(k)
for val in info_dic.values():
print(val)
for k,v in info_dic.items(): #k,v=('name', 'egon')
print(k,v)
长度
info_dic={'name':'egon','age':18,'sex':'male'}
print(len(info_dic))
包含in
info_dic={'name':'egon','age':18,'sex':'male'}
print('name' in info_dic)
print('name' in info_dic.keys())
print('egon' in info_dic.values())
print(('name','egon') in info_dic.items())
掌握
info_dic={'name':'egon','age':18,'sex':'male'}
info_dic.update({'a':1,'name':'Egon'})
print(info_dic)
info_dic['hobbies']=[]
info_dic['hobbies'].append('study')
info_dic['hobbies'].append('read')
print(info_dic)
setdefault:key不存在则设置默认值,并且放回值默认值
key存在则不设置默认,并且返回已经有的值
info_dic.setdefault('hobbies',[1,2])
print(info_dic)
info_dic={'name':'egon','age':18,'sex':'male'}
info_dic.setdefault('hobbies',[1,2,3,4,5])
info_dic.setdefault('hobbies',[1,2,]).append('study')
print(info_dic)
info_dic={'name':'egon','age':18,'sex':'male'}
{'name':'egon','age':18,'sex':'male','hobbies':['study']}
info_dic.setdefault('hobbies',[]).append('study')
{'name':'egon','age':18,'sex':'male','hobbies':['study','read']}
info_dic.setdefault('hobbies',[]).append('read')
{'name':'egon','age':18,'sex':'male','hobbies':['study','read','sleep']}
info_dic.setdefault('hobbies',[]).append('sleep')
l=info_dic.setdefault('hobbies',[])
print(l,id(l))
print(id(info_dic['hobbies']))
print(info_dic)
赋值补充
x=10
链式赋值
a=b=c=d=e=f=10
print(a,b,c,d,e,f)
增量赋值
x=10
y='a'
temp=x
x=y
y=temp
print(x,y)
x,y=y,x
print(x,y)
值的解压
msg='hello'
l=[1,2,3]
a,b,c,d,e=msg
print(a,b,c,d,e)
a,_,_,_,e=msg
a,*_,e=msg
print(a)
print(e)
dic={'a':1,'b':2,'c':3}
x,y,z=dic
print(x,y,z)