python get value from dictionary

Exam = {' Math ': ' n ', ' eng ': ' n ', ' CHN ': ' N ', ' phy ': ', ' Chem ': '} Use the following traversal method to delete: 1. For e in exam:2. If exam[e] = = ':3. Del Exam[e] The result is the following error, How to resolve: Traceback (most recent call last): File "untitled.py", line 3, in Correct procedure: 1. S = {"1": A, "2": B, "3": C, "4":d, "5": E}2. S_key = List (S.keys ())3. For k_s in S_key: 4. #比如我要删除第四个元素 5.del s["4"] Just in the For loop, which is equivalent t

Python Multilevel dictionary value merging:#!/bin/envpythonimportos,sys,reimportcstringiof=open ('/tmp/3.txt ') '/tmp/3.txtcontent :148616 ' 192.168.0.127:8080 ' 0.157{': 130000, ' 206 ':250, ' 301 ':90, ' 302 ':6698, ' 304 ':6018, ' 406 ': 5} 148616 ' 192.168.0.127:8080 ' 0.157{': 130999, ' 206 ':250, ' 301 ':90, ' 302 ':6698, ' 304 ':6018, ' 406 ': 5} 100 ' 1

The examples in this article describe the way Python uses dictionary dict to determine whether a specified key value exists. Share to everyone for your reference. Specific as follows: There are two methods in Python to determine whether a specified key value exists, one is

This example describes how Python can determine whether a specified key value exists through a dictionary dict. Share to everyone for your reference. Specifically as follows: There are two ways in Python to determine whether a specified key value exists, one that is has_key

This article describes how to use the values () method to return the value of the dictionary key in Python. it is a basic knowledge in Python beginners. For more information, see values () returns a list of all available values in a given Dictionary. Syntax The syntax

The Fromkeys () function in Dict can use a list to create a dict with the same initial value.1D = Dict.fromkeys (["Apple","Pineapple"], ['Apple','Pineapple'])2 Print(d)3D.get ("Apple"). Append ('Orange')4 Print(d){' Apple ': [' apple ', ' pineapple '], ' pineapple ': [' apple ', ' pineapple '}{' Apples ': [' apple ', ' pineapple ', ' orange '], ' pineapple ': [' apple ', ' pineapple ', ' orange '}Since the Fromkeys () function was created with

Dictionary value ordering is a pseudo proposition.The dictionary itself cannot be sorted, it has been sorted by keyword (key), but lists (list) and tuples (tuple) can be sorted, so dictionaries need to be sorted after the list is converted.Such asoperatorx = {1234432100}sorted_x = sorted(x.items(), key=operator.itemgetter(1))Is the sort after conversion list, dic

, 32), (9220, 33)]# {9,149:0, 9,150:26, 9,151:24, 9,152:24, 9,153:24, 9,154:27, 9,155:25, 9,156:30, 9,158:20, 9,159:22, 9,160:25, 9,161:21, 91 63:25, 9,164:23, 9,165:25, 9,166:30, 9,167:20, 9,169:25, 9,170:24, 9,171:23, 9,172:25, 9,173:24, 9,174:29, 9,176:27, 9177 : 25, 9,179:25, 9,180:32, 9,181:25, 9,182:25, 9,183:24, 9,184:25, 9,185:25, 9,186:25, 9,188:26, 9,189:20, 9,190:25, 9191: 27, 9,193:24, 9,195:24, 9,196:24, 9,197:23, 9,198:25, 9,199:25, 9,201:24, 9,202:25, 9,203:24, 9,204:25, 9,205:25

Num_dict = {' A ': +, ' B ': ten, ' C ': 8, ' d ': 0} #方法1 # new_dict = sorted (Num_dict.items (), Key=lambda x:x[1]) # Print (Dict (new_d ICT)) #方法2def new_dict (a_dict): b_dict = {} #用于存放排序后的字典 values = sorted (A_dict.values ()) #把16, 10,8,0 sorting Print (values) #打印出 [0, 8, ten,] #接下来要匹配key值 for i in values: for k,v in num_ Dict.items (): #所有的数据项取出来 if v==i: b_dict[k] = v #添加数据项到b_dict字典里 print (b_dict) new_dict (num_ Dict　　

Python dictionary built-in method get application, if we need to get the dictionary value, we have two methods, one is through dict[' key '], and the other is the Dict.get () method. What we are sharing today is the dictionary's

This article mainly introduces the use of the Get () method in Python to obtain the dictionary key value of the tutorial, is the basics of Python introduction, the need for friends can refer to the The Get () method returns the