Python3.5 Dictionary (Dictionary)

Python Dictionary

• A dictionary is another mutable container model and can store any type of object.

• Each key value of the dictionaryKey=>valuePair with a colon:Split, with commas between each key-value pair,Split, the entire dictionary is included in curly braces{}, the format is as follows:

  
  

  D = {Key1 : value1, Key2 : value2

  
  

• The key must be unique, but the value does not have to be.

• The value can take any data type, but the key must be immutable, such as a string, a number, or a tuple.

  
  

• DIC = {' name ': ' Jin ', ' age ': + ' sex ': ' Male '}print (DIC) #{' name ': ' Jin ', ' sex ': ' Male ', ' age ': 18}

  # # # #增 # #

•  #增 # #第一种: There is then overwrite, none add # dic = {' name ': ' Jin ', ' Age ': ', ' sex ': ' Male '}# dic[' hobby '] =  ' Girl ' # print (DIC) #输出 {' Age ': 18,  ' hobby ':  ' girl ',   ' sex ':  ' male ',  ' name ':  ' Jin '}# dic[' name '] =  ' Wusir ' # print (DIC) #{' Age ': 18,  ' sex ':  ' male ',  ' name ':  ' Wusir '}## #第二种:serdefult  None added, there is no change dic =  {' name ': ' Jin ', ' Age ':, ' sex ': ' Male '}# dic.setdefault (' hobby ') # print (dic) #{' sex ':  ' male ',   ' hobby ': none,  ' age ': 18,  ' name ':  ' Jin '}# ' hobby ' is the key, not the value, so the dictionary will appear ' hobby ': none#  dic.setdefault (' Hobby ', ' Girl ') # print (DIC) #{' name ':  ' Jin ',  ' hobby ':  ' girl ',  ' Age ': 18,  ' sex ':  ' male '} #键值对   ' hobby ': Girl added to the dictionary, the original dictionary does not have Hobby# dic.setdefault (' name ', ' Ritian ') # print (DIC) #{' age ': 18,  ' name ':  ' Jin ',  ' sex ':  ' male '} #原字典中有k, name ' so unchanged 

  # # #删 # # #

  
  

•  #pop    has a return value # dic = {' name ': ' Jin ', ' age ': 18, ' Sex ': ' Male '}# print (dic.pop (' Age ')) # #返回所删除键值对的age值18 # print (DIC) # dic.pop (' Hobby ') # #报错 #  Print (Dic.pop (' hobby ', None)) # #设定返回的键值, when hobby does not exist, return none# #clear   empty # dic = {' name ': ' Jin ', ' Age ':, ' sex ': ' Male '}# dic.clear () # print (DIC) #{} empty the dictionary with all key-value pairs # #del # dic = {' name ': ' Jin ', ' Age ':, ' sex ': ' Male '}# del dic# print (DIC) #NameError: name  ' dic '  is  Not defined, by Del dic, has deleted the dictionary dic# dic = {' name ': ' Jin ', ' Age ': ' Sex ': ' Male '}# del  dic[' name ']# print (DIC) #{' age ': 18,  ' sex ':  ' male '}, delete the key value of ' name ' in dic # dic  = {' name ': ' Jin ', ' Age ':, ' sex ': ' Male '}# print (Dic.popitem ()) # print (DIC) #每次随机删除dic里面的键值对 

  # # # #改 #####

  
  

• # dic = {"name": "Jin", "Age": "Sex": "Male"}#  dic[' name '] =  ' Taibai ' # print (DIC) #{' name ':  ' taibai ',  ' sex ':  ' male ',  ' age ':  18 Change the value of the key name #  two dictionary # dic = {"name": "Jin", "Age": "Sex": "Male"}# dic2 = {" Name ":" Alex "," Weight ": 75}# dic2.update (DIC) #将dic键值对, overlay and add to Dic2# print (DIC) #{' age ': 18,  ' Name ':  ' Jin ',  ' sex ':  ' male '}# print (dic2) #{' age ': 18,  ' sex ':  ' male ',  ' Name ':  ' Jin ',  ' weight ':  75} 

  # # # # # # # # # # # # # # #查

# dic = {"name": "Jin", "Age": +, "sex": "Male"}# print (dic[' name ')) #jin the value corresponding to the   check key jin#  print (dic[' name1 ')) #KeyError:  ' name1 ' If you view a key that is not present, an error message # print (dic.get (' name ')) is displayed #jin # print (Dic.get (' name1 ')) #没有此键时默认返回None # print (' Dic.get (' name1 ', ' None of this key value pair ') #无此键值对, can be set later ... # #其它方法 #key ()  values ()   item () dic = {"name": "Jin", "Age": +, "sex": "Male"}# print ( Dic.keys (), type (Dic.keys ())) #查看dic的键keys # print (Dic.keys ()) ## for i in dic.keys (): #      print (i) #列出dic的所有键 # for i in dic:#      print (i) # li = list (Dic.keys ()) #以列表的形式查看dic键 # print (LI) # print (dic.values ()) #值 #  for i in dic.values (): #列出dic的键值 #     print (i) # #items   Random typing of DIC's key values to # print (Dic.items ()) #打出dic的键值对, sequential random #dict_items ([' Age ',  18),  (' Sex ',  ' male '),   (' name ',  ' Jin ')]) # for i iN dic.items (): ##         print (I,type (i)) #  (' name ',   ' Jin ')  <class  ' tuple ' >#  (' sex ',  ' male ')  <class  ' tuple ' >#  (' Age ',  18)  <class  ' tuple ' >

Python3.5 Dictionary (Dictionary)