Python

One, the stringIn Python, a string is an important data type. Other data types are: The number-number-------- int, long, float, complex String-string-------- "Use quotation marks" are quoted as strings.

List.append (Element)#append elements as a listList.clear ()#Clear ListList.copy ()#Copy list (new variable)List.count ()#number of occurrences of statistical elementsList.extend (Element)#append an element in an iterative mannerList.index

1: Both Read and write1With open ('Data', mode='r+', encoding='Utf-8') as F:2 Print(F.read ())#output: Python is closely related to AI3F.write ('Java is good.')4 Print(F.read ())#output: No output, if we want to print5

Beautiful is better than ugly. Beauty is better than uglinessExplicit is better than implicit. Clarity is better than obscuritySimple is better than complex. Simpler than complexComplex is better than complicated. Complexity is better than

The Python version installed by default on CentOS6.9 is 2.6. Because the system comes with Python will be used by many software environments of the system, so do not uninstall the original Python version, as necessary to install the new version, I

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

__get__,__getattr__ and __getattribute are both methods of accessing properties, but they are not the same.Object.__getattr__ (self, name)When attribute is not found in the general position, GetAttr is called, returning a value or Attributeerror

Description: Implement Web login and send and receive messages based on flask framework.Implementation ideas:1. Get the verification code and check if the code is scanned on the phone and confirm login (long polling)2. The user data is initialized

Definition of the function:Functions are well-organized, reusable, code snippets for single, or associated functionalityRole of the function:function can improve the modularity of the application, and the reuse of the CodeAny incoming parameter and

1 ImportOS2 3 #A. File Rename:4Os.rename ("Xxxx.txt","Test.txt")#two parameters, the former is the original file name, the latter is the file name to be replaced5 6 #B. Deleting a file7Os.remove ("Test.txt")#parameter is the file name to be deleted8

Schedule Module Usage1 ImportSchedule2 Import Time3 4 defTest ():5 Print("I ' m working ...")6 deftest2 ():7Print("I ' m working ... in Job2")8 9 #job function executes every 10 minutesTenSchedule.every (10). Minutes.do (Test) One #job

The previous article configured the virtual machine infrastructure environment, this article describes the configuration of the Python development environment Configuring the Yum Source使用国内yum源mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.

multiplexed io (io multiplexing)O multiplexing The word may be a little strange, but if I say select/epoll, probably will understand. Some places also call this IO mode for event-driven IO(Event driven IO). As we all know, the benefit of

Asynchronous IO (asynchronous I/O)The asynchronous IO in Linux is not used much, and is only introduced from kernel version 2.6. Let's take a look at its process:After the user process initiates the read operation, you can begin to do other things

Test:Create a new directory: ATM , three new package conf / bin / module in the directory. and create a new . py file bin.py in package conf . Create a new two file in module logger.py / main.py .1 def logging (): 2 Print ('logging ..... ')

Directly on the code:From numpy Import *Import NumPy as NPDrug_array = Zeros ((708,708), dtype = int)f = open (' D:\mat_drug_drug.txt ')lines = F.readlines ()Drug_row = 0For line in lines: List = Line.strip (' \ n '). Split (') Drug_array[drug_

Blocking io (blocking IO)In Linux, all sockets are blocking by default, and a typical read operation flow is probably this:When the user process invokes the RECVFROM system call, Kernel begins the first phase of IO: Preparing the data. For network

code example:#Coding:utf-8ImportOS fromPyftpdlib.authorizersImportDummyauthorizer fromPyftpdlib.handlersImportFtphandler fromPyftpdlib.serversImportFtpserverdefMain ():#instantiation of User authorization managementAuthorizer =Dummyauthorizer ()

The July programming language index has been released, and Python has continued its upward trend since the first time this May overtook Java, and is gradually widening the gap with Java. (figure is compared with last July data)A brief introduction

Join (): The parent thread of this child thread will remain blocked until the child thread finishes running.Setdaemon (True): Daemon thread. The main thread end does not wait for this child thread to end directly.Import threadingFrom time import