A summary of the dictionary built-in methods in Python

#!/usr/local/bin/python3#-*-coding:utf-8-*-#key-value#dict unordered, no subscript, no subscript required, because there is keystu={' stu001 ': "Zhang Yu", ' stu002 ' : "Ma Hong Yan", ' stu003 ': "Zhang Guo Bin", ' stu004 ': "Sha Chun Hua"} "------------------------------Operation--------------- -------------------------take----------print (stu["stu001") #根据key值取对应的value值--------------------stu[' stu001 ']= ' Tommy Cheung '--------------------stu[' stu005 ']= ' Zhang Zhong Jian '----------delete----------del stu["stu001"] #删除字典中 ' stu001 ' The corresponding key-value pair #del is a built-in common method in Python, not a data type proprietary Stu.pop ("stu001") #同上stu. Popitem () #随机删除stu中的键值对------ ----Check----------print (Stu.get (' stu001 ')) #查找 ' stu001 ' corresponds to the value of print (' stu004 ' in Stu) #判断 ' stu004 ' is in Stu, if it returns true#- ---------Multilevel nesting----------stu2={' a ': {' a1 ': [' A11 ', ' A12 ', ' A13 '], ' A2 ': [' A21 ', ' A22 ', ' A23 '], ' A3 ': [' A31 ', ' A32 ', ' A33 ']}, ' B ': {' B1 ': [' B11 ', ' B12 ', ' B13 '], ' B2 ': [' B21 ', ' B22 ', ' B23 '], ' B3 ': [' B31 ', ' b32 ', ' B33 ']}, ' C ': {' C1 ': [' C11 ', ' C12 ',' C13 ', ' C2 ': [' C21 ', ' C22 ', ' c23 '], ' C3 ': [' c31 ', ' c32 ', ' C33 ']}}stu2[' b ' [' B1 '][2]= ' BBB ' Print (STU2)--------- -Traverse----------for I in Stu: #遍历的两种方法, it is recommended to use the first print (I,stu[i]) for x, y in Stu.items (): Print (x, y)--------------------- ---------method----------------------------------------Print a key or value value----------print (Stu.keys ()) print (Stu.values ())                                                ----------added----------stu.setdefault (' stu001 ', {' C0 ': [' c01 ', ' C02 ']}) #先从stu中去取 the value of the key corresponding to ' stu000 ' #如果可以取到, the value is returned; #如果取不到, the new key-value pair is created in Stu----------             Update----------a={' A1 ': ' A11 '}b={' A1 ': ' A12 ', ' B1 ': ' B11 '}a.update (b) #将b更新到a, if there is a duplicate key in A and B, the value corresponding to key in B is updated to a #若b中有新key, add it to the A in print (a) #结果: {' a1 ': ' A12 ', ' B1 ': ' B11 '}----------convert Key-value value to list-tuple----------print (stu.i TEMs ()) print (Stu) "

　　

A summary of the dictionary built-in methods in Python