Thursday, 25 June 2015

Data Scraping - Enjoy the Appeal of the Hand Scraped Flooring

Hand scraped flooring is appreciated for the character it brings into the home. This style of flooring relies on hand scraped planks of wood and not the precise milled boards. The irregularities in the planks provide a certain degree of charm and help to create a more unique feature in the home.

Distressed vs. Hand scraped

There are two types of flooring in the market that have an aged and unique charm with a non perfect finish. However, there is a significant difference in the process used to manufacture the planks. The more standard distresses flooring is cut on a factory production line. The grooves, scratches, dents, or other irregularities in these planks are part of the manufacturing process and achieved by rolling or pressed the wood onto a patterned surface.

The real hand scraped planks are made by craftsmen and they work on each plant individually. By using this working technique, there is complete certainty that each plank will be unique in appearance.

Scraping the planks

The hand scraping process on the highest-quality planks is completed by the trained carpenter or craftsmen who will produce a high-quality end product and take great care in their workmanship. It can benefit to ask the supplier of the flooring to see who completes the work.

Beside the well scraped lumber, there are also those planks that have been bought from the less than desirable sources. This is caused by the increased demand for this type of flooring. At the lower end of the market the unskilled workers are used and the end results aren't so impressive.

The high-quality plank has the distinctive look that feels and functions perfectly well as solid flooring, while the low-quality work can appear quite ugly and cheap.

Even though it might cost a little bit more, it benefits to source the hardwood floor dealers that rely on the skilled workers to complete the scraping process.

Buying the right lumber

Once a genuine supplier is found, it is necessary to determine the finer aspects of the wooden flooring. This hand scraped flooring is available in several hardwoods, such as oak, cherry, hickory, and walnut. Plus, it comes in many different sizes and widths. A further aspect relates to the finish with darker colored woods more effective at highlighting the character of the scraped boards. This makes the shadows and lines appear more prominent once the planks have been installed at home.

Why not visit Bellacerafloors.com for the latest collection of luxury floor materials, including the Handscraped Hardwood Flooring.

Source: http://ezinearticles.com/?Enjoy-the-Appeal-of-the-Hand-Scraped-Flooring&id=8995784

Saturday, 20 June 2015

Web Scraping: working with APIs

APIs present researchers with a diverse set of data sources through a standardised access mechanism: send a pasted together HTTP request, receive JSON or XML in return. Today we tap into a range of APIs to get comfortable sending queries and processing responses.

These are the slides from the final class in Web Scraping through R: Web scraping for the humanities and social sciences

This week we explore how to use APIs in R, focusing on the Google Maps API. We then attempt to transfer this approach to query the Yandex Maps API. Finally, the practice section includes examples of working with the YouTube V2 API, a few ‘social’ APIs such as LinkedIn and Twitter, as well as APIs less off the beaten track (Cricket scores, anyone?).

I enjoyed teaching this course and hope to repeat and improve on it next year. When designing the course I tried to cram in everything I wish I had been taught early on in my PhD (resulting in information overload, I fear). Still, hopefully it has been useful to students getting started with digital data collection, showing on the one hand what is possible, and on the other giving some idea of key steps in achieving research objectives.

Download the .Rpres file to use in Rstudio here

A regular R script with code-snippets only can be accessed here

Slides from the first session here

Slides from the second session here

Slides from the third session here

Source: http://www.r-bloggers.com/web-scraping-working-with-apis/

Monday, 8 June 2015

Web Scraping Services : Data Discovery vs. Data Extraction

Looking at screen-scraping at a simplified level, there are two primary stages involved: data discovery and data extraction. Data discovery deals with navigating a web site to arrive at the pages containing the data you want, and data extraction deals with actually pulling that data off of those pages. Generally when people think of screen-scraping they focus on the data extraction portion of the process, but my experience has been that data discovery is often the more difficult of the two.

The data discovery step in screen-scraping might be as simple as requesting a single URL. For example, you might just need to go to the home page of a site and extract out the latest news headlines. On the other side of the spectrum, data discovery may involve logging in to a web site, traversing a series of pages in order to get needed cookies, submitting a POST request on a search form, traversing through search results pages, and finally following all of the "details" links within the search results pages to get to the data you're actually after. In cases of the former a simple Perl script would often work just fine. For anything much more complex than that, though, a commercial screen-scraping tool can be an incredible time-saver. Especially for sites that require logging in, writing code to handle screen-scraping can be a nightmare when it comes to dealing with cookies and such.

In the data extraction phase you've already arrived at the page containing the data you're interested in, and you now need to pull it out of the HTML. Traditionally this has typically involved creating a series of regular expressions that match the pieces of the page you want (e.g., URL's and link titles). Regular expressions can be a bit complex to deal with, so most screen-scraping applications will hide these details from you, even though they may use regular expressions behind the scenes.

As an addendum, I should probably mention a third phase that is often ignored, and that is, what do you do with the data once you've extracted it? Common examples include writing the data to a CSV or XML file, or saving it to a database. In the case of a live web site you might even scrape the information and display it in the user's web browser in real-time. When shopping around for a screen-scraping tool you should make sure that it gives you the flexibility you need to work with the data once it's been extracted.

Source: http://ezinearticles.com/?Data-Discovery-vs.-Data-Extraction&id=165396

Tuesday, 2 June 2015

On-line directory tree webscraping

As you surf around the internet — particularly in the old days — you may have seen web-pages like this:

The former image is generated by Apache SVN server, and the latter is the plain directory view generated for UserDir on Apache.

In both cases you have a very primitive page that allows you to surf up and down the directory tree of the resource (either the SVN repository or a directory file system) and select links to resources that correspond to particular files.

Now, a file system can be thought of as a simple key-value store for these resources burdened by an awkward set of conventions for listing the keys where you keep being obstructed by the ‘/‘ character.

My objective is to provide a module that makes it easy to iterate through these directory trees and produce a flat table with the following helpful entries:

Although there is clearly redundant data between the fields url, abspath, fname, name, ext, having them in there makes it much easier to build a useful front end.

The function code (which I won’t copy in here) is at https://scraperwiki.com/scrapers/apache_directory_tree_extractor/. This contains the functions ParseSVNRevPage(url) and ParseSVNRevPageTree(url), both of which return dicts of the form:

{'url', 'rev', 'dirname', 'svnrepo',

 'contents':[{'url', 'abspath', 'fname', 'name', 'ext'}]}

I haven’t written the code for parsing the Apache Directory view yet, but for now we have something we can use.

I scraped the UK Cave Data Registry with this scraper which simply applies the ParseSVNRevPageTree() function to each of the links and glues the output into a flat array before saving it:

lrdata = ParseSVNRevPageTree(href)

ldata = [ ]

for cres in lrdata["contents"]:

    cres["svnrepo"], cres["rev"] = lrdata["svnrepo"], lrdata["rev"]

    ldata.append(cres)

scraperwiki.sqlite.save(["svnrepo", "rev", "abspath"], ldata)

Now that we have a large table of links, we can make the cave image file viewer based on the query:

select abspath, url, svnrepo from swdata where ext=’.jpg’ order by abspath limit 500

By clicking on a reference to a jpg resource on the left, you can preview what it looks like on the right.

If you want to know why the page is muddy, a video of the conditions in which the data was gathered is here.

Image files are usually the most immediately interesting out of any unknown file system dump. And they can be made more interesting by associating meta-data with them (given that no convention for including interesting information in the EXIF sections of their file formats). This meta-data might be floating around in other files dumped into the same repository — eg in the form of links to them from html pages which relate to picture captions.

But that is a future scraping project for another time.

Source: https://scraperwiki.wordpress.com/2012/09/14/on-line-directory-tree-webscraping/