Python

1. What is BytesioBytesio is similar to Stringio, except that Stringio can only store String,bytesio for storing bytes, which provides the ability to read and write bytes in memory.That is, read and write strings in memory using Stringio, read-write

classsingleobj (): __singleobj=None @classmethod def get_singleinstance (CLS):ifNot cls.__singleobj:cls.__singleobj=singleobj ()returncls.__singleobjobj1=singleobj.get_singleinstance () print (obj1) obj2=singleobj.get_singleinstance () print (OBJ2)

Reference Blog: http://www.cnblogs.com/lincj/p/5617605.htmlFirst, Os.walk ()Os.walk (Top, Topdown=true, Onerror=none, Followlinks=false)Can get a ternary tupple (Dirpath, Dirnames, filenames),The first is the starting path, the second is the folder

1. Module ImportImport xxx or from xxx import xxx, try to avoid using from XXX import *2. Variables, constantsLocal variables: can only be used within a function or within a class to assign values and change valuesGlobal variables: Can be used in

Shutil advanced files, directories, compression package processing modulesImport ShutilCopyShutil.copyfileobj (F1,F2) #从一个文件对接复制到另一个文件对象 need to open the fileShutil.copyfile () #拷贝文件Shutil.copystat () #只拷贝文件状态信息 including

MapThe map() function receives two arguments, one is the function, the other is to function the Iterable map incoming function to each element of the sequence sequentially, and returns the result as a new one Iterator .That is, map (function,

==commands module = = (Unix only) the "commands" module contains some functions for executing external commands. [Example 3-7 #eg-3-7] shows this module. ====example 3-7. Use commands module ====[eg-3-7] "' file:commands-example-1.pyimport

1 #initializing the nodes of a linked list2 classNode ():3 def __init__(Self,item):4Self.item =Item5Self.next =None6 7 #Incoming header node, gets the length of the entire list8 defLength (headnode):9 ifHeadnode = =None:Ten

Shutil Module I. Shutil moduleThe main function with the copy file is used.1.shutil.copyfileobj (file 1, file 2): Overwrite the data in file 1 with copy to file 2.Import= open ("1.txt", encoding="utf-8 " = open ("2.txt","w", encoding="

What is object-oriented An object, that is, a specific individual in an abstract class of things. Everything that exists in this world is an object, and it can be created if it doesn't exist. Compared to process-oriented differences:

What is a list?A list consists of a series of elements arranged in a particular order. The list looks like this: [1,2,3,4,1]. In a list, you can consist of 0 or more elements, separated by commas, with the same value element allowing multiple

Multi-processThe Unix/linux operating system provides a fork() system call, which is very special. A normal function call, called once, is returned once, but fork() called once, and returned two times, because the operating system automatically

There are two methods in Python to determine whether a specified key value exists, one is judged by the method of the Dictionary object, and the other is through the in method, the following is a detailed example of Has_key. 123

1 classNode ():2 def __init__(Self,item):3 #Initialize this node, the value and the next point4Self.item =Item5Self.next =None6 7 classsinglelinklist ():8 def __init__(self):9 #Initialize the single-linked list with a null

BackgroundRecent interest has written several Python libraries, also published on the PyPI, although no one to download, but they are used on other machines will be very convenient. Here I will show you how to publish your own Python library on PyPI.

When developing Python projects, it is necessary to create multiple Python virtual environments in a virtual environment, because different projects require different resource bundles and related configurations.Install the virtual

JavaScript SupplementJavaScript RegularTest-Determines whether a string conforms to the regular rep =/\d+/;rep.test ("Asdfoiklfasdf89asdfasdf") # Truerep =/^\d+$/;//plus ^ (first) $ (tail) All strings must conform to the specified regular rep.test ("

See tutorial See Let write a three login error lock user job, but the tutorial did not say how to write.Write your own always error in that judge entered the account and password where, and then go to the Internet to see someone wrote this,1 #they

Tag: Performer implements coding factory encapsulated object Border connection Ges useFactory method Pattern (Factory mode): Defines an interface for creating objects, so that subclasses decide which class to instantiate, and the factory method

Baptism soul, practice python (58)-crawler-[reprinted] urllib3 module, pythonurllib3Urllib31. Overview Compared with urllib and urlib2, urllib3 has some new functions to implement many things. This module is special and can also exist in python2 and