Python

A. struct moduleThe module can convert a type to a fixed-length bytesImport Structlst = [1,2,4,3,5,]lst1 = [1,2,4,3,5,7,8,9= struct.pack ('i', Len (LST)) # Convert the length of the list to a fixed 4 byte b = Struct.pack('i', Len (lst1))Print (A,

Crawl High Stealth Agent1 fromUrllibImportRequest2 ImportRe3 Import Time4 5f = open ('West 1.csv','W', encoding='GBK')6headers = {7 'Cookies':'_free_proxy_session=

# Headline Street Pat picture Crawl1 ImportRe2 ImportRequests3 fromUrllibImportRequest4 ImportJSON5 ImportOS6i =07headers = {8 'user-agent':'mozilla/5.0 (Windows NT 10.0; WOW64) applewebkit/537.36 (khtml, like Gecko) chrome/68.0.3440.106 safari/

This method is defined in object, so all modern classes inherit the method, and all instances of the new class are called when the property value is obtained, and in order to verify this conclusion, we rewrite the method:classC (object): a='ABC'

the queue module in Python is commonly used to handle queuing-related issuesqueues are often used in producer consumer models, with the main function of improving efficiency and decoupling programs1. Basic use of the queue module and related

#Loop list Don't delete thingsLis = [11,22,33,44,55]#For i in range (len (LIS)):#print (i)#del Lis[i]#print (LIS) #报错, #because each deleted element is the next list after the deletion, #This causes the list to not be indexed after#Delete Odd

1, Bytes and ByteArray# bytes: immutable byte sequence; ByteArray: byte array, variable data type;(1) Bytes definitionclass bytes (object): """ (1) bytes (iterable_of_ints), Bytes (2) bytes (string, encoding[, errors]), Bytes (3) bytes

1 #Author:cgq2 ImportCopy3 #List4 " "5 names=["Zhangyang", "Xiaohei", "Xiaohei", "Lisan"]6 print (names[0]) #某一个7 #切片8 print (Names[1:3])9 print (Names[0:-1:2]) #2代表步长Ten print (names[-1]) One print (names[-2:]) A - Print (Names[names.index

Installing Virtualenvpip install virtualenvCreate a virtual environmentvirtualenv testdirGo to this directoryActivate.bat access to the virtual environmentDeactivate.bat exiting the virtual environmentThe virtual environment needs us to know the

1:2-point methodFirst of all, introduce the dichotomy methodBinary search, can eliminate half of the data each time, the search efficiency is very high, but the limitations are relatively large, must be ordered sequence can be used to find the

Use QQ mailbox to send mail, need to apply for QQ email Authorization Code#Coding=utf-8ImportSmtplib,sys fromEmail.mime.textImportMimetextclassmsmtp ():def __init__(self, target, subject, content):#recipient, title, ContentSelf.msg_from ='the

PythonBuilt-in filter ()The function is used to filter the sequence. Like map () ,filter () also receives a function and a sequence. Unlike map () ,filter () applies the incoming function to each element sequentially, and then decides whether to

This chapter describes the use of circles to circle circles using the python language : #!/usr/bin/python#-*-coding:utf-8-*-if __name__ = = ' __main__ ': from Tkinter import * canvas = canvas (width=80 0, height=600, bg= ' yellow '

Let's look at this article today. python os.access () method . In this article, we learn about Python os.acces, a method that you've never seen before, and a way to understand its definition and role, and it's nonsense to say that we're starting to

Let's take a look at the Python OS in this article today. Chown () method, in the next article we will introduce the Python Os.chown () method, chown and chmod look very similar, but the two are completely different methods, in the next article I

SQLiteis an embedded database, and its database is a file. Because SQLiteIt is written in C and small in size, so it is often integrated into a variety of applications, even in iOS and Android apps. python has built-in SQLite3, so using SQLitein

Let's look at this article today. Pythonwrite (), I'll explain it in this article. the Write method in Python as well as the Pythonwrite property , and it can be used in Python programming where to explain. No more nonsense, let's get started.

This article describes the python multithreading, want to know python multithreading, you have to understand what is Threads。 A thread is the smallest unit that the operating system can perform operations on. It is included in the process and is

In this article, let's look at the python ReadLines Method, before we enter the article, we first need to know PythonreadlinesWhat is it ReadLines ()It can be used in Python programming where it can play a role. These things we can all learn in

In this article, let's look at the Fileno in Python (), before we go into the article we first need to know what we are going to learn, and we don't know what it is. Because today is about Pythonfileno ()and explaining what Fileno () means to you.