Python dictionary operations

A key-value data type, used as a dictionary of our school, to check the details of the corresponding page by strokes and letters.

Grammar:

#!/usr/bin/env python#-*-Coding:utf-8-*-info = {' stu1101 ': ' Tenglan Wu ', ' stu1102 ': ' Longze luola ', ' stu110 3 ': "Xiaoze Maliya",}print (info) execution result: {' stu1103 ': ' Xiaoze maliya ', ' stu1102 ': ' Longze luola ', ' stu1101 ': ' Tenglan Wu ' }

Features of the dictionary:

• Dict is disordered.

• Key must be unique and so is inherently heavy

Increase

>>> info["stu1104"] = "Cang jing Empty" >>> info{' stu1102 ': ' Longze luola ', ' stu1104 ': ' Cang jing empty ', ' stu1103 ': ' Xiaoze Mal Iya ', ' stu1101 ': ' Tenglan Wu '}

Modify

>>> info[' stu1101 ' = "Enrique" >>> info{' stu1102 ': ' Longze luola ', ' stu1103 ': ' Xiaoze maliya ', ' stu1101 ': ' Enrique '}

Delete

>>> info{' stu1102 ':  ' Longze luola ',  ' stu1103 ':  ' Xiaoze maliya ',  ' stu1101 ':  ' Enrique '}>>> info.pop ("stu1101")  # Standard removal posture ' enrique ' >>> info{' stu1102 ':  ' Longze luola ',  ' stu1103 ':  ' xiaoze  Maliya '}>>> del info[' stu1103 ']  #换个姿势删除 >>> info{' stu1102 ':  ' LongZe  luola '}>>> >>> >>> >>> info = {' stu1102 ':  ' Longze luola ',  ' stu1103 ":  ' Xiaoze maliya '}>>> info{' stu1102 ' :  ' Longze luola ',  ' stu1103 ':  ' Xiaoze maliya '}  #随机删除 >>>  Info.popitem () (' stu1102 ',  ' Longze luola ') >>> info{' stu1103 ':  ' Xiaoze maliya ' }

Find

>>> info = {' stu1102 ': ' Longze luola ', ' stu1103 ': ' Xiaoze maliya '}>>> >>> ' stu1102 ' in info #标准 Usage true>>> info.get ("stu1102") #获取 ' Longze luola ' >>> info["stu1102"] #同上, but look below ' Longze Luola ' >>  > info["stu1105"] #如果一个key不存在, error, get no, not exist only return Nonetraceback (most recent call last): File "<stdin>", line 1, in <module>keyerror: ' stu1105 '

multilevel dictionary nesting and manipulation

av_catalog = {     "Europe and America":{          "www.youporn.com":  ["a lot of free, the world's largest", "Quality General"],          "www.pornhub.com":  ["a lot of free, also very big", "quality than Yourporn High"],          "letmedothistoyou.com":  ["Many are selfies, high-quality pictures many", "resources are not many, update slow"],          "x-art.com": ["high quality, really high", "all charges, Dick than please bypass"]    },     "Japan and Korea" :{         "Tokyo-hot": ["How the quality is not clear, the individual has not liked the Japanese and Korean fan", "Heard is the fee"]     },     "mainland":{         "1024": ["All free, really good, A good man's life is safe "," the server in foreign countries, slow "]    }}av_catalog[" "["] "][1] += ", you can crawl down with the crawler "Print (av_ catalog["mainland" ["1024x768"]) #ouput  [' All free, really good, a good person life safe ',  ' server is abroad, slow, can crawl down with crawlers '] 

other poses

#values >>> info.values () dict_values ([' Longze luola ',  ' Xiaoze maliya ']) #keys > >> info.keys () Dict_keys ([' stu1102 ',  ' stu1103 ']) #setdefault >>> info.setdefault (" Stu1106 "," Alex ") ' Alex ' >>> info{' stu1102 ':  ' Longze luola ',  ' stu1103 ':  ' Xiaoze  maliya ',  ' stu1106 ':  ' Alex '}>>> info.setdefault ("stu1102", "deflorating la") ' longze  Luola ' >>> info{' stu1102 ':  ' Longze luola ',  ' stu1103 ',:  ' Xiaoze maliya ',   ' stu1106 ':  ' Alex '} #update  >>> info{' stu1102 ':  ' Longze luola ',  ' stu1103 ':  ' Xiaoze maliya ',  ' stu1106 ':  ' Alex '}>>> b = {1:2,3:4,   "stu1102": "Deflorating"}>>> info.update (b) >>> info{' stu1102 ':  ' deflorating ',  1:  2, 3: 4,  ' stu1103 ':  ' Xiaoze maliya ',  ' stu1106 ':  ' Alex '}# Itemsinfo.items () Dict_items ([(' Stu1102',  ' deflorating '),  (1, 2),  (3, 4),  (' stu1103 ',  ' Xiaoze maliya '),  (' stu1106 ',  ' Alex ')] #通过一个列表生成默认dict, there is no way to explain the pit, less use this >>> dict.fromkeys ([three-way], ' testd ') {1:   ' testd ', 2:  ' testd ', 3:  ' testd '}

Cyclic dict

#方法1for key in Info:print (Key,info[key]) #方法2for k,v in Info.items (): #会先把dict转成list, do not use print (K,V) when the data is large

This article is from the "Little Rookie" blog, please be sure to keep this source http://baishuchao.blog.51cto.com/12918589/1935077

Python dictionary operations