Scraping html WITHOUT uniquie identifiers using python [closed] - python

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I would like to design an algorithm using python that scrapes thousands of pages like this one and this one, gathers all the data and inserts it into a MySQL database. The script will be run on a weekly or bi-weekly basis to update the database of any new information added to each individual page.
Ideally I would like a scraper that is easy to work with for table structured data but also data that does not have unique identifiers (ie. id and classes attributes).
Which scraper add-on should I use? BeautifulSoup, Scrapy or Mechanize?
Are there any particular tutorials/books I should be looking at for this desired result?
In the long-run I will be implementing a mobile app that works with all this data through querying the database.

first thought:
(in order to save some time) Have you seen thewaybackmachine? http://archive.org/web/
2nd thought:
If you are going to develop a mobile app then the layout of this site doesn't lend itself to be put on handheld devices easily. I would suggest not bothering with the webpage portion of this. You are just going to have to dig all the information out eventually and change your scrappers each time they change some little thing on their website.
You can get the data from their developer API in Json or CSV format.
From the raw data you can make it into whatever format you want. (for personal use only according to their site)
Caveats:
Pay attention to the robots.txt file on the site.
http://www.robotstxt.org/robotstxt.html
If they don't want to be scrapped they will tell you so. You can do this for personal use, but if you try making money from their content you will find yourself sued.

You could use lxml, which can take XPath specifiers. It takes a while to get used to the XPath syntax, but it's useful in cases like this.

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Is there a not-relational database for python? [closed]

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I am searching something like sqlite but not-relational. In other words I would like to work with a triple-store (a set of object-predicate-subject triplets) instead of tables. It means that I want to use SPARQL queries instead of SQL.
The first idea that comes into mind is RDFLib. However, I see two problems with this option:
RDFLib is not a data base and, as a consequence, it is not designed to work with parallel process (for example with parallel request induced by many web-users). It might lead to inconsistencies if two users at the same time try to add to or delete from the triple-store.
RDFLib is designed to work with RDF, which is a particular implementation (syntax) of the triple-store. For example, each object, predicate and subject have to have URI and I do not have them. In my triple-store I would like to have triplets like that: ("Washington","is capital of", "USA") (so, no URI).
SPARQL is explicitly for RDF; if you want to use it you'll need to create your own ontology or utilise existing ones.
I recommend taking a look at ORDF with 4store as the back-end.
As the commenters already said, there is a wrapper interface for SPARQL - the SPARQL Endpoint interface to Python (currently in version 1.6.0):
http://rdflib.github.io/sparqlwrapper/
I also came across another thread discussing non-relational databases with Python, although it doesn't specifically mention SPARQL: portable non-relational database
While it doesn't have a whole lot to it, this guide for Python SPARQL developers has some pointers: http://www.openlinksw.com/blog/~kidehen/?id=1651

Getting started with API in django [closed]

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I am confused as to how APIs work with django in general. I am looking to get started but am a bit confused where to start. I am fairly new to django but have mastered most of the basics.
I am looking to understand how to communicate with other REST apis, how to send and receive json data, what is needed for this data(where does it live, are models required?, do I create views to access json data?)
I am looking for a comprehensive tutorial or book/article that I can follow that will teach me the ins and outs of this. Any help on where to get started would be much appreciated.
Django is for web development. If what you want to do is get JSON from some remote RESTful service, no part of that requires Django. Instead, try urllib or httplib2, and check simple examples elsewhere.
Again, sending JSON data is a simple as using the json library in python, and using the same urllib tricks you use to consume JSON from other people. So no django needed there either.
As for whether models are required, well that depends 100% on what you're trying to do. Your question about needing "views" on json data I think confuses several different issues.
I'd recommend you read up on RESTful services in general, and where JSON fits before you start implementation.

MongoDB aggregation REST [closed]

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I'm reading around and see that it is a bad idea to have remote application talk directly to my MongoDB e.g. install a Mongodb driver in a phone app. The best way is to have a REST interface on a server to talk between the database and the end user. But what about the aggregation framework?
I see Sleepy.mongoose and Eve but I cannot see anything about aggregation.
Is there any way/or REST interface which allows you to make aggregation calls (I'm interested in subdocuments)?
E.g. requesting $ curl 'http://localhost:27080/customFunction/Restaurant' and return all the subdocuments matching shop.kind with Restaurant.
I'm familiar with python and java, is there any API framework that allows you to do that?
Before you get flagged as off-topic as you likely will for asking for opinions and not a specific programming question I'll just say one bit. Hopefully on-topic.
I highly doubt that most projects will go beyond being a basic CRUD adaptor allowing you access to collection objects and sometimes (badly) database objects. Is with their various ORM backed counterparts they will do doubt allow a similar query syntax to be executed from the client, so queries could be composed and sent through as JSON, which will not surprisingly look much like (identical) to the standard query syntax for MongoDB.
For myself I prefer to roll my own, and largely because you may want to implement a lot of customer behavior and actions, and in some way abstract a little from having a lot of CRUD code in the client. Let's face it, you're probably passing through and passing JSON that is going into the native structures you're using anyway. So it's not hard really. Anyhow, each to his own I suppose.
There is a listing of other implementations on available here:
http://docs.mongodb.org/ecosystem/tools/http-interfaces/

tools for Crawling popular forum/bulletin board software [closed]

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I've started writing a crawler to crawl vbulletin boards. However, I am not a web programmer (json api's I can do, but that isn't really web-crawling), and as such I do not know what the best way to crawl is, and what tools are available.
I am more than capable of writing the crawler, but the I find the underlying HTML very irregular, and so I don't want to be a victim of the structure of the HTML changing in a newer version of vbulletin.
I'm writing an interface using pycurl and beautiful soup. However, is there a better way to do this, are there any good crawlers already available for vbulletin ? (language is not a concern). A meta forum crawler (works with more than one forum type) would be even better.
If you cannot suggest one, could you advise me, if you have the experience, from what I should expect from the stability of the underlying HTML, should I worry about a new version of vbulletin breaking my crawler ?
Perhaps there is a better way to extract a vbulletin dataset ?
Having HTML change is an inherit issue with webcrawling. That is why it should only be an absolute last resort. Maintaining crawlers can be a huge task, as you have seen, because HTML can change daily and there are no guarentees.
Because the data that is usually being searched for is uniform, scrapy is an excellent choice.
http://doc.scrapy.org/en/0.14/index.html
It uses xpath to select elements, which is relatively easy to mainatin imo.
Even if there is a vbulletin specific scraper it is still dependent on HTML which can break at will. Because vbulletin is a platform you are probably pretty well off scraping it. I would think HTML would only change on version updates which shouldn't be that often.
Does the mobile API provide you with any functionality you need?
https://www.vbulletin.com/forum/content.php/367-API-Overview, I guess this depends on per site vbulletin setup.

Test how my website appears to a program [closed]

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A website may be accessed not only by a user on a browser, but also programs, bots and crawlers. I have a website running on Google App Engine with python which has non-static HTML pages that are generated by a python program by combining, merging and looping strings. However, they are also not dynamic pages in the sense that no user input is required to generate these pages. The content generation by python is solely for convenience, brevity and ease of maintenance, and is set completely by the url.
Some search engines cannot index dynamic pages. I would like to know if these pages qualify as 'dynamic', i.e. whether they can be crawled or indexed for the usual metadata and content by such bots, and in general would like a way to check how any url appears to a bot or crawler like the ones used by search engines, so that I can see when a certain url is uncrawlable.
If anyone knows of any resources or techniques available, it'd be really helpful.
Some search engines cannot index dynamic pages.
Not true. Clients cannot know and do not care if the server got the content by executing a script or just reading a static file.
Most search engines won't execute client side JavaScript. Most search engines will not submit forms.
If your content is accessible by following links (that are in the HTML), then search engines can get the pages.
Lynx is a text-based browser that gives you a pretty good idea of how a searchbot would see your page. Ancient, tried and true.

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