python dictionary of dictionaries

This article describes examples of conversion between dictionaries and JSON in Python. This article provides examples of conversion from Dict to JSON, reading JSON, and converting to Dict, for more information, see JSON. it is a lightweight data exchange format with good support in various languages. A dictionary is a data structure of

1. String: ' content ' storage of small amounts of dataIndex: Is the subscript is starting from 0s = ' Python automation learning 'S1 = s[0]Print (S1) #通过索引找到元素Slice: is a paragraph, "0:4" Gu Tou disregard tails = ' Python automation learning '#通过切片查找pythonS1 = S[0:6]Print (S1)Step: Skip to fetchs = ' Python automation learning '#通过跳着切片查找S2 = S[:5:2] #0可以省略Print

Constant definition rule: constant meaning is not changed; Constant definition name is all uppercase;such as: mysql_connection= ' 192.168.1.1 'Pyc:python generated translation files that enable the computer to recognize the Python language;Syntax and use of the list:List parameter insertion syntax: Name.insert (2, ' Minggou ')NAME[1] = "Wangminglong"---> Modify the contents of the corresponding field in the list;Append: Name.append ("Alex")Delete: Nam

1. List and String conversionsList -to-string:Stitching the contents of a list into a stringTo convert a value in a list to a stringString goto list:Convert each character of a string to a value in a listSplit a string into a list2. List and dictionary conversionList to Dictionary:Turn two lists into dictionariesConvert nested lists to dictionariesDictionary goto list:Dictionary key, value to listConversion between

个字典' Zhang San ': {' 2018.3.23 ': ' Not delivered ', ' 2018.3.24 ': ' Delivered '},' John Doe ': {' 2018.3.23 ': ' Delivered ', ' 2018.3.24 ': ' Delivered '},' Liu Wu ': {' 2018.3.23 ': ' Not delivered ', ' 2018.3.24 ': ' Not Delivered '},}For I in range (3): #进入三次循环Operation = input ("'1. View Student Assignments2. Entry of student assignmentsPlease select the action you want to do: "). Strip ()if operation = = ' 1 ': #选择查看学生信息, print out all student informationFor k,v in Homeworks.items ():Pri

"" White Time: January 9, 2018 demand: Suppose you have a lot of cars, By constantly asking if you want to add a vehicle to your inventory, if you do, then it will ask for details of the car. If not, the application prints the details of all cars and exits. function: Loop to add information about the car and record information into the dictionary "" "Defmain (): car_list= []whiletrue:add_inventory= input (' Do you want to add car info? (y/n): ') i

This article corresponds to exercise 39 dictionaries and cute dictionaries. # Encoding: UTF-8 # differences between the list and dictionary # list thing = ['name', 1, 'age', 'ad ', 'sex'] print thing [1] # print thing ['name'] # An error is returned. The list can only be accessed through an integer: TypeError: list indices must be integers, not strstuff = {'nam

simplest example is the user information stored in the dictionary, and then through the user input key, take out the user's corresponding information, please see the following example:Dict = {' Name ': ' da ',' Age ': 25,' Sex ': Nan}If the user wants to remove the age value based on key, it can be:Print (Dict.get (' age ')) = 25This method I use less, that is, when the key exists to change value, if it does not exist, add it into; when I write a scr

preferences. However, the Attrgetter () function typically runs faster and allows multiple fields to be compared at the same time. This is similar to the Operator.itemgetter () function for dictionary types (refer to section 1.13). For example, if the user instance also has a first_name and last_name property, you can sort the following:By_name = sorted (Users, Key=attrgetter (' last_name ', ' first_name '))It is also important to note that the techn

This article mainly introduces the use of the SetDefault () method of manipulating dictionaries in Python, which is the basic knowledge in Python's introductory study, and the friends who need it can refer to The SetDefault () method is similar to the Get () method, but sets the dictionary [key]= default if the key is not already in the