- Re: [Tutor] memory error « python-tutor « ActiveState List Archives
- Web Scraping using Python
- List Archives
- Web scraping with Scrapy and Beautiful Soup
Why bother so when HTML in itself is presenting text in a given structure. Instead of text match and regex, we could just parse. What are Parsers? As we already know, the content we are parsing might belong to various encodings. BS4 automatically detects it. To install this package with conda run: conda install -c anaconda beautifulsoup4. To install this package with conda run: conda install -c anaconda lxml. Our recommendations If your web scraping needs are simple, then any of the above tools might be easy to pick up and implement. If you are looking for some professional help with scraping complex websites, let us know by filling up the form below.
Tell us about your complex web scraping projects Turn the Internet into meaningful, structured and usable data. Disclaimer: Any code provided in our tutorials is for illustration and learning purposes only. We are not responsible for how it is used and assume no liability for any detrimental usage of the source code. The mere presence of this code on our site does not imply that we encourage scraping or scrape the websites referenced in the code and accompanying tutorial.
The tutorials only help illustrate the technique of programming web scrapers for popular internet websites. We are not obligated to provide any support for the code, however, if you add your questions in the comments section, we may periodically address them.
Re: [Tutor] memory error « python-tutor « ActiveState List Archives
Continue Reading.. In this part we talk about Web Scraping, some history and go deep into parts of a web scraper. We also take a look the programming…. Puppeteer is a node. In this tutorial post, we will show you how to build a web scraper and…. If you need publicly available data from scraping the Internet, before creating a web scraper, it is best to check if this data is already available from public data sources or APIs.
With our page collected, parsed, and set up as a BeautifulSoup object, we can move on to collecting the data that we would like. Whatever data you would like to collect, you need to find out how it is described by the DOM of the web page. Within the context menu that pops up, you should see a menu item similar to Inspect Element Firefox or Inspect Chrome. Once you click on the relevant Inspect menu item, the tools for web developers should appear within your browser.
This is important to note so that we only search for text within this section of the web page. We also notice that the name Zabaglia, Niccola is in a link tag, since the name references a web page that describes the artist. We can therefore use Beautiful Soup to find the AlphaNav class and use the decompose method to remove a tag from the parse tree and then destroy it along with its contents.
Note that we are iterating over the list above by calling on the index number of each item. However, what if we want to also capture the URLs associated with those artists? Although we are now getting information from the website, it is currently just printing to our terminal window. Collecting data that only lives in a terminal window is not very useful.
Web Scraping using Python
Comma-separated values CSV files allow us to store tabular data in plain text, and is a common format for spreadsheets and databases. Before beginning with this section, you should familiarize yourself with how to handle plain text files in Python. When you run the program now with the python command, no output will be returned to your terminal window. Instead, a file will be created in the directory you are working in called z-artist-names. We have created a program that will pull data from the first page of the list of artists whose last names start with the letter Z.
However, there are 4 pages in total of these artists available on the website. In order to collect all of these pages, we can perform more iterations with for loops. This will revise most of the code we have written so far, but will employ similar concepts. Since there are 4 pages for the letter Z , we constructed the for loop above with a range of 1 to 5 so that it will iterate through each of the 4 pages. We will concatenate these strings together and then append the result to the pages list.
The code in this for loop will look similar to the code we have created so far, as it is doing the task we completed for the first page of the letter Z artists for each of the 4 pages total.
Note that because we have put the original program into the second for loop, we now have the original loop as a nested for loop contained in it. These two for loops come below the import statements, the CSV file creation and writer with the line for writing the headers of the file , and the initialization of the pages variable assigned to a list. I briefly looked into doing this. The answer is pretty damn difficult, at least in the case of mozilla. Actually, I think it would be pretty easy if you are willing to have a running Mozilla process. I use a similar technique to get emacs to syntax-highlight my slides.
Connect to the running emacs with all my settings , run htmlify via emacsclient --eval, and enjoy perfect highlighting!
Web scraping with Scrapy and Beautiful Soup
Sorry, yes -- I definitely don't want a running mozilla process. Plus it's not at all clear that it's possible to run mozilla headless, though I didn't look that hard. You can run any X app headless with Xvfb. Ah, cool -- it's just that my servers don't run X. Or really have enough ram to spare to add 30 copies of X, mozilla, and other associated stuff. I really just need a relatively compact parsing engine. I'm not sure why you would need 30 copies of X or Mozilla.
Either way, it is kind of inelegant, but it is hard to pick-and-choose parts of Mozilla. That, however, may not be necessary. Lately, I've been using libxml2, and that has also worked very well. Zero problems. This is so unfortunate. It's such a great piece of software that so many of us depend on. It's really too bad that there's not enough money in it for Leonard to keep it up. But, I have no bitterness, just thanks! Your title really rubs me the wrong way. This isn't bitrot, it's actually quite the opposite: the problem showed up because he does actively maintain the code, he made the latest release compatible with future versions of the standard Python distribution.
He's standing up to say he's going to honor his responsibility to this code even though he doesn't enjoy it anymore, but that that doesn't include writing html parsers, and you come along and scream 'bitrot'. Sorry, but that's kind of an assholish thing of you to do. Its performance is getting worse over time because maintaining its speed requires more maintenance than anyone is willing to give it, at least so far. I would call that bit rot too. I think both of you agree that the original author deserves only thanks. But that's not what the linked article is about at all.
If you have benchmarks and you want to write that article, by all means, do it.
I think you must have woken up on the wrong side of the bed. I certainly had no intention of impugning the author of the code, and in fact, I thanked him with the thread-opening comment. We can across the behavior he describes in building TrailBehind, and I just thought I'd share with the community. As for bit rot, that's a pretty old term that just means code breaks down as it ages. It's one of those things that you can say about your own project, or in pointing out a specific problem within a codebase, but to say it about a project as a whole that has an active maintainer especially after he releases an update to avoid bit rot going forward and then asks for help dealing with the upstream problems , that's assholish.