python web scraping example

a label cannot be found after the site is revised to throw an exception.fromimport urlopenfromimport= urlopen("http://www.pythonscraping.com/pages/page1.html")try: = BeautifulSoup(html.read(),"lxml") = bsObj.ul.li print(li)exceptAttributeErroras e: print(e)‘NoneType‘ object has no attribute ‘li‘4. First Reptile Program fromUrllib.requestImportUrlopen fromUrllib.errorImportHttperror fromBs4ImportBeautifulSoupdefGetTitle (URL):Try: HTML=Urlopen (URL)exceptHttperror asE:return None

Best Web scraping books-for this post, we have scraped various signals (e.g. online ratings and reviews, topics covered , author influence in the field, year of publication, social media mentions, etc.) From the web about web scraping books. We have fed all above signals to

software, refer to this document: collections of Web scraping software and server2. Web scraping frameworkThe scraping framework is probably the best choice for developer because it is powerful and efficient, and has a framework for different platforms to choose from, such

In this textbook, we assume that you have installed the scrapy. If you are not installed, you can refer to this installation guide. We will use the Open Directory Project (DMOZ) As our example to crawl. This textbook will take you through the following areas: Create a new Scrapy project Define the item that you will extract Write a spider to crawl the site and extract items. Write an item pipeline to store the proposed items Scr

In this textbook, we assume that you have installed the scrapy. If you do not have the installation, you can refer to this installation guide. We will use the Open Directory Project (DMOZ) As our example to crawl. This textbook will take you through the following areas: To create a new Scrapy project Define the item that you will extract Write a spider to crawl the site and extract items. Write an item pipeline to store the items prese

Example of web crawler in python core programming, python core programming Crawler 1 #!/usr/bin/env python 2 3 import cStringIO # 4 import formatter # 5 from htmllib import HTMLParser # We use various classes in these modu

This article mainly introduces the python web page capture example (python crawler). For more information, see the following code: #-*-Encoding: UTF-8 -*-'''Created on 2014-4-24 @ Author: Leon Wong''' Import urllib2Import urllibImport reImport timeImport OSImport uuid # Obtain the url of the second-level pageDef findU

Python has two features as follows: Explanatory language Gil Global Interpreter Lock The former causes its performance to be naturally in the compiled language to lag behind a lot of performance. The latter, in the era of multi-core parallel computing, greatly limits the Python application scenario. However, with a reasonable web framework,

results in the most commonly used JSON, with the following commands: Scrapy Crawl Dmoz-o items.json-t JSON -O is followed by the export file name, and-T followed by the export type. Then take a look at the results of the export, open the JSON file with a text editor (for easy display, delete the attribute except the title in item): Because this is just a small example, so simple processing is possible. If you want to use the crawled items to do some

/Computers/Programming/Languages/Python/Books/", "http:// Www.dmoz.org/Computers/Programming/Languages/Python/Resources/" ] def parse (self, response): filename = Response.url.split ("/") [-2] open (filename, ' WB '). Write (Response.body) Allow_domains is the domain name range of the search, which is the restricted area of the reptile, which stipulates that the crawler only

, it can discard a task (perhaps this particular page has just been crawled), or assign a different priority to the task. When the priority of each task is determined, they are passed in to the crawler. It crawls the page again. The process is complex, but logically simpler. When the resources on the network are crawled down, the content handler is responsible for extracting the useful information. It runs a user-written Python script that is not qu

Python Pyspider is used as an example to analyze the web crawler implementation method of the search engine. In this article, we will analyze a web crawler. Web Crawler is a tool that scans Network Content and records its useful information. It can open a lot of

Use the Python Flask framework to construct the structure example of a large Web application, pythonflask Although small web applications can be easily expanded with a single script, this method cannot be well expanded. As the application becomes more complex, processing in a single large source file becomes more and m

Code example for asynchronous processing of Python Web framework Tornado1. What is Tornado Tornado is a lightweight but high-performance Python web framework. Compared with another popular Python

Example of using MongoDB in Python Web framework Pylons This article describes how to use MongoDB in Python Web framework Pylons. Python 1.0 was released after a long development. For formal product development, version 1.0 is of

Selenium is a tool that allows the browser to automate a series of tasks, often used for automated testing. However, it can also be used to give Web pages. Currently, it supports four client languages for Java, C #, Ruby, and Python. If you use Python, you only need to enter "sudo easy_install selenium" on the command line and return to install Selenium's

# print result. read () self. deal_data (result. read (). decode ('gbk') self. calculate_date (); # extract the content from the page code def deal_data (self, myPage): myItems = re. findall ('.*? (.*?) .*? (.*?) .*?', MyPage, re. s) # obtain credits for item in myItems: self. weights. append (item [0]. encode ('gbk') self. points. append (item [1]. encode ('gbk') # calculate the score. if the score is not displayed or the score is excellent, def calculate_date (self) is not ca

This article mainly introduces the use of Python program to crawl the HTML information of a small example, the use of the method is also the basis for the use of Python to write reptiles, the need for friends can refer to the There are a number of ideas to crawl Web data, generally: Direct code request HTTP, Analog br

Python provides an example of how to capture a web page to generate an Excel file, This example describes how to capture a web page and generate an Excel file using Python. We will share this with you for your reference. The deta

The code and tools usedSample site source + Framework + book pdf+ Chapter codeLink: https://pan.baidu.com/s/1miHjIYk Password: af35Environmentpython2.7Win7x64Sample Site SetupWswp-places.zip in the book site source codeFrames used by the Web2py_src.zip site1 Decompression Web2py_src.zip2 then go to the Web2py/applications directory3 Extract the Wswp-places.zip to the applications directory4 return to the previous level directory, to the Web2py directory, double-click web2py.py, or execute comman