字典常用方法

 

字典的表示方法：info_dic={'name':'haiyna','age':18,'sex':'female'}# 常用操作：#1.存/取info_dic={'name':'egon','age':18,'sex':'male'}  print(info_dic['name11111111'])#找不到则报错了  print(info_dic.get('name',None))  print(info_dic.get('name222222',None))#get方法找不到不报错，可以自己设定默认值#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)) # # 　　　　循环 # # 　　　　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.setdefault('hobbies',[1,2,3,4,5]) # print(info_dic) # info_dic={'name':'haiyan','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) #了解 # d=info_dic.copy() # print(d) # info_dic.clear() # print(info_dic) # d=info_dic.fromkeys(('name','age','sex'),None) # print(d) # d1=dict.fromkeys(('name','age','sex'),None) # d2=dict.fromkeys(('name','age','sex'),('egon',18,'male')) # print(d1) # print(d2) # info=dict(name='haiyan',age=18,sex='male') # print(info) # # info=dict([('name','haiyan'),('age',18)]) # print(info)