Python

First, what is a variableVariables are one of the language features of all programming languages, so it's important to understand variables when you want to learn programming. So what is a variable? From the name of the main divided into two parts

QueueThe queue is similar to a pipe, the element is first out, in put(arg) ,get()One thing to note is that the queue is in-memory operation, the process exits, the queue is emptied , and the queue is a blocking pattern.Queue classificationQueues

Article Source: http://www.cnblogs.com/wupeiqi/articles/5040823.htmlThe Socketserver internally uses IO multiplexing and "multithreading" and "multi-process" to enable the socket service side to process multiple client requests concurrently. That is,

Describes some of the advanced topics about classes, which are optional and are not often encountered in Python applications.==========================================================================Slots InstancesAssigns a string property name

Describes some of the advanced topics about classes, which are optional and are not often encountered in Python applications.==========================================================================Slots InstancesAssigns a string property name

One, Global interpreter lock (GIL)1, what is the global interpreter lockIn the same process, whenever one thread acquires the use rights of the Global Interpreter (CPU), the other threads must wait for the global Interpreter (CPU) of the thread to

1.if judgmentIn Python programming, if statements are used in the execution of control programs, in the basic form:If judgment condition: EXECUTE statement else: EXECUTE statement In Python, use indentation instead of curly braces in the C

I. OverviewSorting has an internal sort and an external sort, the internal sort is the data record is sorted in memory, and the external sort is because the sorted data is large, one cannot hold all the sort records at a time, and the external

First, the module:1. Any Python program can be imported as a module. Use sys.Write a hello.py program and save it to the D:\python directory.2, the module is used to define: all classes and functions are defined and the assigned variables become the

One, type variable data type: The data type inner element value can be changed in the case of constant IDSuch as: list, dictionary immutable data type:value changed, ID changedsuch as: Numbers, Strings, BooleanAdded: True------>1False----->0Second,

Python djangorestframework Installation Library error ssl:certificate_verify_failed problem descriptionUse PIP to follow virtualenv error, as follows:Pip install djangorestframeworkcollecting djangorestframework not fetch URL https://

I. Data types and variables 1. Variable and immutable data typesVariable data type: The element inside the data type can be changed in the case of the same IDListDictionaryImmutable data type: value changed, ID changedDigitalStringBooleanAdd:True--->

FileName: Creates a filedhandler with the specified file name (the concept of handler is explained in the back) so that the log is stored in the specified file. FileMode: File is opened by using this parameter when filename is specified, and the

Isinstance (OBJ,CLS) and Issubclass (Sub,super)Isinstance (obj,cls) checks if obj is an object of class CLS, if True is returned1 class Foo (object): 2 pass3 obj = Foo () 4 print (Isinstance (obj, foo))Issubclass (sub, super) checks if the sub

Django solves the problem of cross-domain requests solution 1. Install Django-cors-headerspip install django-cors-headers内容详见：https://github.com/ottoyiu/django-cors-headersOther solutions 1. Using JSONPWhen using AJAX to get JSON data, using

Novice programming partners will have some doubts about the use of deep-level copies, today we will combine the characteristics of the Python variable storage from the memory point of view to talk about assignment and depth copy ~ ~ ~The variable

Queue Queue is a thread-safe queuing (FIFO) implementation in the Python standard library, providing a first-in-one data structure for multithreaded programming, a queue that is used to transfer information between producers and consumer

1,str () and repr () STR () is intended to be readable, repr () to make the results clear and unambiguous There's not much difference between the two. 2, it is recommended to use the following. Format () to print: Print (' A is {} and B is {} '.

Iterators Iteration is one of the most powerful features of Python and is a way to access the elements of a collection. An iterator is an object that remembers where to traverse. The iterator object is accessed from the first element of the

The so-called Web crawl, is the URL address specified in the network resources from the network stream read out, save to Local. There are many libraries in python that can be used to crawl Web pages, so let's learn urllib.request first. (for URLLIB2