Python

ImportNumPy as NPA=np.array ([A])PrintAB=np.array ([[1,2],[3,4]])PrintbPrintNp.arange (1,5,0.5)#less than 5PrintNp.random.random ((2,2))#2*2 Random floating-point arrayPrintNp.linspace (1,2,10,endpoint=False)PrintNp.linspace (1,2,10)#The default 2

We open Sina News, see the page below, first to crawl a level URL, the picture of the Blue circle sectionSecond zh picture, display need paging,Source:#Coding:utf-8ImportJSONImportRedisImport TimeImportrequestssession=requests.session

1: What is an iteration in statement, the program automatically invokes the iterator object of the object being processed, and then uses its next__ () method until a Stopiteration exception is detected.>>> L = [n/A]>>> [x**2 for x in L][1, 4, 9]>>>

Written in the previous words: 2017 There are too many distractions and slack. Things are stagnant in many ways, and the end-of-year version is still a problem, deeply remorse and uneasy. Hope that the coming year will be serious, focus and

1 classPerson ():2 def __init__(self, name):3Self.name =name4 5 6 defPrint_name (self):7 Print(Self.name)8 9p = Person ('Li')Ten ImportTypes OneP.print_name =types. Methodtype (Print_name, p) # bind function to Object A P.print_name () - -

Project Name: personalized recommendation of watercress BooksRequirements Brief: from a given watercress user name, get the user all Watercress friends list, from the Watercress friends to find out they have read and rated 5 stars of the book, if

The index of the list (subscript) starts at 0 and the last one can be represented by-1.1. Add ( append (), insert ())2. Delete (pop (), remove (), Del, Clear ())Stus.pop () #默认删除最后一个Stus.pop (1) #删除指定位置Stus.remove (' Nancy ') #删除list中某个元素, with

slices(intercept element, can operate list,tuple,string)L = List (range) # [0,1,2,3,...,]l[0:10] = l[:10] # intercept the first 10 numbers [0,1,2,..., 9 ]# l[-10: # 10 numbers after intercept [90,91,92,...,]l[10:20] # intercept elements

--------Blogs: Chen http://www.cnblogs.com/chenyuebai -------- I. OverviewWhen she works, she needs to inquire a lot of information about trains to Nanjing , including the arrival station ( Nanjing Station or Nanjing South Railway station), arrival

DictPython built-in dictionary: dict support, Dict full name dictionary, in other languages also known as map, using key-value (Key-value) storage, with a very fast search speed.For example, suppose you want to find the corresponding score according

has been studying scrapy data capture, in the study of Ajax data capture happened to study the selenium, is really practical, but only to do scrapy under the data crawl, not suitable, one is the loss of performance, has to open a browser, and the

Directory random forest Principle random Forest code (Spark Python) Random Forest Principles to be continued ...Back to Catalog Random Forest Code (Spark Python) 　　Code data:

This is a case of using XPath, for more information, see: Python Learning Guide Case: Crawler using XPathNow we use XPath to make a simple crawler, we try to crawl all the posts in a bar and download the images from each floor of the post to

One, thread-based parallel programming How to use the Python threading module How to define a thread How to probe a thread How to use threads in a subclass Lockand RLock Implement thread synchronization Signal

Socket is a way of inter-process communication, and other processes of communication between the main difference is: to achieve inter-process communication between different hosts, the network of a variety of services are based on the socket to

Module: PsutilPsutil is a cross-platform library that makes it easy for us to get information about the process and resource utilization of the system running.Function: mainly for the system monitoringInstallation:wget

This article mainly for you to share a Python read CSV file to remove a column and then write a new file instance, has a very valuable reference, I hope to help you. Follow the small part together to see it, hope to help everyone better grasp the

Prefetch count -- Prefetch count, prefetchcount --I. Preface As mentioned above, if multiple consumers subscribe to messages in the same Queue at the same time, messages in the Queue will be evenly distributed to multiple consumers. At this time, if

Python 3.6.4/win10 when using pip to install keras, an error occurred while installing the dependent PyYAML, win10keras PS C:\Users\myjac\Desktop\simple-chinese-ocr> pip install kerasCollecting keras Downloading

Python installation and development environment setup, python Development and Building1. Check "Add Python 3.5 to PATH" on the official website: "Environment". You do not need to configure environment variables, then select install now 2. You can