Python

began to learn the Python database programming, in the understanding of the basic concept, intends to start experimenting, stuck in the installation of the MYSQLDB package, toss a half a day to solve. Record the problems I encountered installing

Python operation MySQLImport Pymysql"CREATE DATABASE Connection"Conn =pymysql.connect (host= ' localhost ', port=3306,user= ' root ', db= ' test ');' Create cursor 'Cursor =conn.cursor ()"Execute a single SQL"Effect_row = Cursor.execute ("INSERT

Function: evaluates the string str as a valid expression and returns the result of the calculation.Syntax: eval (source[, globals[, locals]), valueParameters:Source: The code object returned by a Python expression or function compile ()Globals:

##author: Wuhao##爬取指定页码的图片, if you need to crawl all the pictures of a certain category, the overall frame will not change, but you need to analyze it separately#Import Urllib.requestImport Urllib.parseImport reImport OS#添加headerHeader=\{

1.any () functionAny (iterable)->boolReturns ture if one of the iterators is ture, or False if Interable=null.>>> any ([1,0])True>>> any ([0,0])False>>> any ([])False>>> any ([1,0,0])TrueApplication: In a binary tree, find the largest element in

1) Python developed by Guido2) compile (compile) type: Generate an executable file directly from the compiler using the code.For example, to translate English books into Chinese books at once. Languages are: c,c++, etc.Interpreted: Side-compilation

Remember regular expression is a very headache, but as long as the collation of good, a little practice will be very good to remember ...Locator characters^ matches the beginning of a string, such as ^itcast, that matches a string beginning with

First, comments‘‘‘Multi-line comments‘‘‘#单行注释"' #example1.1 Test program time: 4/17/2017I1=input ("Please enter user name:")I2=input ("Please enter password")Print (I1)Print (I2)Print ("ainiyou")‘‘‘Second, the variable1) (the rules are the same as

File system features: OS moduleWhen Python is programmed, it often deals with files and directories, which is not the OS module. The OS module contains common operating system features, regardless of the specific platform. The following lists the

Because the CPU and memory speed is much higher than the speed of the peripheral, so in IO programming, there is a serious problem of speed mismatch. For example, for example, to write 100M data to disk, the CPU output 100M of data only need 0.01

Set: A set of different elements that form a collection, which is the basic data type of Python. Set Classification: Variable set (set), immutable set (Frozenset), created in the same way as set features: unordered, unique, fast1. Create a

Collections is a python built-in collection module that provides a number of useful collection classes. The 1.Counter counter Counter is a simple counter, for example, the number of statistical characters that appear: >>> Importcollections>>> obj

Detailed explanation of how Python processes XML format data and pythonxml format This article describes how Python processes XML format data. We will share this with you for your reference. The details are as follows: The operation here is based on

Use python to write a script for Timed Shutdown in windows (recommended ). Because I often use laptops to share WiFi, but I don't want my laptop to start up for one night (for the sake of low carbon and Environmental Protection ~ _~!), So every time

Python crawls music URLs in qq music and downloads them in batches. pythonurl Preface There are still a lot of music on qq music, and sometimes you want to download nice music, but every time you download it on the web page, it is annoying to log on

Use Python to create Windows and python Services Recently, a Python program needs to be installed and run as a Windows system service. Some pitfalls have been encountered during the process. Python service class First, the Python program must call

Details about Python multi-thread instances and python multi-thread instances Detailed description of Python multi-thread instances Multithreading is usually a new background thread to process time-consuming operations. It is also very easy for

Details about how to obtain snmp information and performance tests concurrently in python, pythonsnmp Python & snmp Multiple existing libraries can be used to obtain snmp information using python.netsnmpAndpysnmpTwo databases. There are many

Difference between is and = in Python, and difference between pythonis In Python, if two objects (variables) are equal, you can use the "is" and "=" operations. But what is the difference between them? When is "is" and when is "=" used "? During the

Python crawler Cookie usage, pythoncookie Cookie refers to the data (usually encrypted) stored on the user's local terminal by some websites to identify users and track sessions) For example, some websites need to log on before they can access a