Python Development Basics: Dictionary Operations

One, dictionary operation

1 #!/usr/bin/env python2 #_*_coding:utf-8_*_3 4 5 #Common operations:6 #7 #Deposit/Withdraw8 #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '}9 #print (info_dic[' name11111111 ')) #没有这个key, errorTen #Print (Info_dic.get (' name1 ', None)) #最好用get取值, no case returns none, you can define your own return of this none One  A #Pop:key If there is a popup value, does not exist then returns the default value, if there is no default then the error - #Print (Info_dic.pop (' name ', None)) - #print (info_dic) the  - #print (Info_dic.popitem ()) #随机删除 - #print (info_dic) -  + #info_dic[' level ']=10 #添加 - #print (info_dic) +  A # at #Delete - #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} - #Info_dic.pop () - #Info_dic.popitem () - #del info_dic[' name '] -  in  - # to #key S, value s, key value pairs + #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} - #print (Info_dic.keys ()) the #print (Info_dic.values ()) * #print (Info_dic.items ()) $ Panax Notoginseng #For K in Info_dic: - ## Print (k,info_dic[k]) the #print (k) +  A #print (' ========> ') the #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 ') the #print (k,v) - Wuyi  the  - #length Wu #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} - #print (len (info_dic)) About # $ #Loops - # - #contains in default alignment is key -  A #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} + #print (' name ' in Info_dic) the #print (' name ' in Info_dic.keys ()) - #print (' Egon ' in Info_dic.values ()) $ #print (' name ', ' Egon ') in Info_dic.items ()) the  the  the #Master the #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} - #info_dic.update ({' A ': 1, ' name ': ' Egon '}) #有的话就是覆盖, no words are added in #print (info_dic) the  the #info_dic[' Hobbies ']=[] About #info_dic[' Hobbies '].append (' study ') the #info_dic[' Hobbies '].append (' read ') the #print (info_dic) the  + #Setdefault:key The default value is not present, and adds the default value to the values - #key is not set by default and returns the existing value the Bayi #info_dic.setdefault (' hobbies ', [up]) the #print (info_dic) the #info_dic.setdefault (' hobbies ', [1,2,3,4,5]) - #print (info_dic) -  the #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '} the  the #{' name ': ' Egon ', ' age ':, ' sex ': ' Male ', ' hobbies ': [' study ']} the #info_dic.setdefault (' hobbies ', []). Append (' study ') - #print (info_dic) the  the #{' name ': ' Egon ', ' age ':, ' sex ': ' Male ', ' hobbies ': [' study ', ' read '} the #info_dic.setdefault (' hobbies ', []). Append (' read ')94 #print (info_dic) the  the #{' name ': ' Egon ', ' age ':, ' sex ': ' Male ', ' hobbies ': [' study ', ' read ', ' Sleep ']} the #info_dic.setdefault (' hobbies ', []). Append (' Sleep ')98 #info_dic.setdefault (' hobbies ', []). Append (' read ') About #l=info_dic.setdefault (' hobbies ', []) - #Print (L,id (l))101 #Print (Info_dic,id (info_dic[' hobbies ') )102 103 #info_dic.setdefault (' hobbies ', ' a ') #都可以, id all the same104 #info_dic.setdefault (' hobbies ', {1}) the ## Info_dic.setdefault (' Hobbies ', (2))106 #l=info_dic.setdefault (' hobbies ', {})107 #Print (L,id (l))108 #Print (Info_dic,id (info_dic[' hobbies ') )109  the 111 #Understand the #d=info_dic.copy ()113 #print (d) the #info_dic.clear () the #print (info_dic) the 117 #info_dic={' name ': ' Egon ', ' age ':, ' sex ': ' Male '}118 #D=info_dic.fromkeys (' name ', ' age ', ' sex '), None) #格式化, changing values to None,none can be any119 #print (d) - #D1=dict.fromkeys (' name ', ' age ', ' sex '), None)121 #D2=dict.fromkeys (' name ', ' age ', ' sex '), (' Egon ', ' Male ')122 #print (D1)123 #print (D2)124 # the #info=dict (name= ' Egon ', age=18,sex= ' male ') #字典写法126 #Print (info)127  - #info=dict ([' Name ', ' Egon '), (' Age ',)]) #字典写法129 #Print (info)

Python Development Basics: Dictionary Operations