Python

__slots__What if we want to restrict the properties of class? For example, only add and attributes to student instances are allowed name age .For the purpose of limiting, Python allows you to define a special variable when defining a class __slots__

UnitTestTest outcomesTests have 3 possible outcomes:OkThe test passes.FAILThe test does not a pass, and raises an Assertionerror exception.ERRORThe test raises an exception and other than Assertionerror.Asserting Truthclass truthtest (unittest.

When you open a. py file, you will often see if __name__ = = ' __main__ ' at the bottom of the code: Now let's introduce its role.The module is an object, and all modules have a built-in property of __name__. The value of the __name__ of a module

First, save the following code as opennote.pyimport Sys,osos.system (sys.argv[1]) command-line window execution: opennote.py notepadThe magical effect appeared, automatically opened the Notepad program;Parse: sys.argv[] is used to get command line

Python module configparser operation INI Format fileCat Test.txt[Host]WEB01 = 10.10.10.10WEB02 = 20.20.20.20[db]MYSQL01 = 1.1.1.1MYSQL02 = 2.2.2.2#!/usr/bin/env python#coding: UTF8Import Configparser,string,os,sysCF = Configparser.configparser

Input and output:Open ()Read ()Readine ()ReadLines ()Write ()The Pickle module can do serialization operations, persisting object information.We can easily read and write the strings in the file. The value will be a little more trouble, because the

--Split Code start----Import Sys,os;kilobytes = 1024;megabytes = kilobytes*1024;chunksize = Int (10*megabytes);def split (Fromfile,todir,chunksize=chunksize):If not os.path.exists (Todir):Os.mkdir (Todir)ElseFor fname in Os.listdir (todir):Os.remove

Python is an object-oriented and interpretive computer programming language, is a powerful and perfect general-purpose language, has more than 10 years of development history, mature and stable. Python has the richest and most powerful class library

Today wrote a program, due to design problems, resulting in two modules need to reference each other, there is a "importerror" error. For a long analysis, there are two methods for module cycle-dependent problems:1, can be resolved by adjusting

Preface: Colleagues encounter a problem, need to find a No. 7000 file in tens of thousands of files, messy ... The Python-related information was checked, though not completely resolved, but something was recorded.One, to a folder to traverse the

ProblemIn the work often uses the socket transmits the data, for example the client sends the data to the server (both sides agreed the data format), before the test, uses the python to write the server which accepts the data, parses the data format

AttributeError at/home/Exception Type: AttributeError at/home/, attributeerror "Error message ": Environment: Request Method: GET Request URL: http: // localhost: 8000/home/ Django Version: 1.7.5 Python Version: 2.7.0 Installed Applications:

Python: How to Create a hidden window sub-process in windows This example describes how to create a hidden window sub-process in python in windows. Share it with you for your reference. The specific implementation method is as follows: Import

Python uses multiprocessing to create a process. This example describes how to create a process using multiprocessing in Python. Share it with you for your reference. The specific analysis is as follows: The Process can be created by calling the

Python avoids deadlock Method Instance analysis, and python avoids instance analysis This article describes how to avoid deadlocks in python. Share it with you for your reference. The specific analysis is as follows: When two or more threads are

Python pipeline usage example, python Pipeline This example describes how to use pipelines in python. Share it with you for your reference. The details are as follows: #! Coding = utf-8import multiprocessingdef consumer (pipe): output_p, input_p =

Learning notes: Python 2.7 is commonly used for time and date, python2.7 Two methods to obtain the current time import datetime,timenow = time.strftime("%Y-%m-%d %H:%M:%S")print nownow = datetime.datetime.now()print now   Obtains the hour before the

Python Learning Series (9) (IO and Exception Handling) and pythonio Python Learning Series (9) (IO and Exception Handling) Python Learning Series (8) (Object-Oriented basics) I. Storage 1. Python provides a standard module called pickle, which can

Python yield, pythonyield I saw the yield keyword in other people's code, read some documents, and explain my understanding.   A function that contains the yield keyword becomes an iterator. yield is at the same position as return, but does not

Python to delete expired files, This example describes how to delete expired files in python. Share it with you for your reference. The specific implementation method is as follows: # remove all jpeg image files of an expired modification date =