Package: scrapple
ScrappleScrappleis a framework for
creating web scrapers and web crawlers according to a key-value based
configuration file. It provides a command line interface to run the
script on a given JSON-based configuration input, as well as a web
interface to provide the necessary input.The primary goal of Scrapple is to abstract the process of designing web
content extractors. The focus is laid on what to extract, rather than
how to do it. The user-specified configuration file contains selector
expressions (XPath expressions or CSS selectors) and the attribute to be
selected. Scrapple does the work of running this extractor, without the
user worrying about writing a program. Scrapple can also be used to
generate a Python script that implements the desired extractor.InstallationYou can install Scrapple by using$ sudo apt-get install libxml2-dev libxslt-dev python-dev lib32z1-dev
$ pip install scrappleOtherwise, you could clone this repository and install the package.$ git clone http://github.com/scrappleapp/scrapple scrapple
$ cd scrapple
$ pip install -r requirements.txt
$ python setup.py installHow to use ScrappleScrapple provides 4 commands to create and implement extractors.genconfiggeneraterunwebScrapple implements the desired extractor on the basis of the
user-specified configuration file. There are guidelines regarding how to
write these configuration files.The configuration file is the basic specification of the extractor
required. It contains the URL for the web page to be loaded, the
selector expressions for the data to be extracted and in the case of
crawlers, the selector expression for the links to be crawled through.The keys used in the configuration file are :project_name: Specifies the name of the project with which the
configuration file is associated.selector_type: Specifies the type of selector expressions used.
This could be “xpath” or “css”.scraping: Specifies parameters for the extractor to be created.url: Specifies the URL of the base web page to be loaded.data: Specifies a list of selectors for the data to be
extracted.selector: Specifies the selector expression.attr: Specifies the attribute to be extracted from the
result of the selector expression.field: Specifies the field name under which this data is
to stored.default: Specifies the default value to be used if the
selector expression fails.table: Specifies a description for scraping tabular data.table_type: Specifies the type of table (“rows” or
“columns”). This determines the type of table to be extracted.
A row extraction is when there is a single row to be extracted
and mapped to a set of headers. A column extraction is when a
set of rows have to be extracted, giving a list of header-value
mappings.header: Specifies the headers to be used for the table.
This can be a list of headers, or a selector that gives the
list of headers.prefix: Specifies a prefix to be added to each header.suffix: Specifies a suffix to be added to each header.selector: Specifies the selector for the data. For row
extraction, this is a selector that gives the row to be
extracted. For column extraction, this is a list of selectors
for each column.attr: Specifies the attribute to be extracted from the
selected tag.default: Specifies the default value to be used if the
selector does not return any data.next: Specifies the crawler implementation.follow_link: Specifies the selector expression for the<a>tags to be crawled through.The main objective of the configuration file is to specify extraction
rules in terms of selector expressions and the attribute to be
extracted. There are certain set forms of selector/attribute value pairs
that perform various types of content extraction.Selector expressions :CSS selector or XPath expressions that specify the tag to be
selected.“url” to take the URL of the current page on which extraction is
being performed.Attribute selectors :“text” to extract the textual content from that tag.“href”, “src” etc., to extract any of the other attributes of the
selected tag.Tutorials[For a more detailed tutorial, check out thetutorial in the
documentation]In this simple example for using Scrapple, we’ll extract NBA player
information fromthe ESPN website.To first create the skeleton configuration file, we use the genconfig
command.$ scrapple genconfig nba http://espn.go.com/nba/teams --type=crawler --levels=2This creates nba.json - a sample Scrapple configuration file for a
crawler, which uses XPath expressions as selectors. This can be edited
and the required follow link selector, data selectors and attributes can
be specified.{"project_name":"nba","selector_type":"xpath","scraping":{"url":"http://espn.go.com/nba/teams","data":[{"field":"","selector":"","attr":"","default":""}],"next":[{"follow_link":"//*[@class='mod-content']//a[3]","scraping":{"data":[{"field":"team","selector":"//h2","attr":"text","default":"<no_team>"}],"next":[{"follow_link":"//*[@class='mod-content']/table[1]//tr[@class!='colhead']//a","scraping":{"data":[{"field":"name","selector":"//h1","attr":"text","default":"<no_name>"},{"field":"headshot_link","selector":"//*[@class='main-headshot']/img","attr":"src","default":"<no_image>"},{"field":"number & position","selector":"//ul[@class='general-info']/li[1]","attr":"text","default":"<00> #<GFC>"}],"table":[{"table_type":"rows","header":"//div[@class='player-stats']//table//th","prefix":"season_","suffix":"","selector":"//div[@class='player-stats']//table//tr[1]/td","attr":"text","default":""},{"table_type":"rows","header":"//div[@class='player-stats']//table//th","prefix":"career_","suffix":"","selector":"//div[@class='player-stats']//table//tr[@class='career']/td","attr":"text","default":""}]}}]}}]}}The extractor can be run using the run command -$ scrapple run nba nba_players -o jsonThis creates nba_players.json which contains the extracted data. An
example snippet of this data :{"project":"nba","data":[#nba_players.jsoncontinues{"career_APG":"9.9","career_PER":"","career_PPG":"18.6","career_RPG":"4.4","headshot_link":"http://a.espncdn.com/combiner/i?img=/i/headshots/nba/players/full/2779.png&w=350&h=254","name":"Chris Paul","number & position":"#3 PG","season_APG":"9.2","season_PER":"23.49","season_PPG":"17.6","season_RPG":"3.5","team":"Los Angeles Clippers"},{"career_APG":"3.6","career_PER":"","career_PPG":"20.3","career_RPG":"5.8","headshot_link":"http://a.espncdn.com/combiner/i?img=/i/headshots/nba/players/full/662.png&w=350&h=254","name":"Paul Pierce","number & position":"#34 SF","season_APG":"0.9","season_PER":"7.55","season_PPG":"5.0","season_RPG":"2.6","team":"Los Angeles Clippers"},{"career_APG":"2.9","career_PER":"","career_PPG":"3.7","career_RPG":"1.8","headshot_link":"http://a.espncdn.com/combiner/i?img=/i/headshots/nba/players/full/4182.png&w=350&h=254","name":"Pablo Prigioni","number & position":"#9 PG","season_APG":"1.9","season_PER":"8.72","season_PPG":"2.3","season_RPG":"1.5","team":"Los Angeles Clippers"},{"career_APG":"2.0","career_PER":"","career_PPG":"11.1","career_RPG":"1.9","headshot_link":"http://a.espncdn.com/combiner/i?img=/i/headshots/nba/players/full/3024.png&w=350&h=254","name":"J.J. Redick","number & position":"#4 SG","season_APG":"1.6","season_PER":"18.10","season_PPG":"15.9","season_RPG":"1.5","team":"Los Angeles Clippers"},#nba_players.jsoncontinues]}The run command can also be used to create a CSV file with the extracted
data, using the –output_type=csv argument.The generate command can be used to generate a Python script that
implements this extractor. In essence, it replicates the execution of
the run command.$ scrapple generate nba nba_script -o jsonThis creates nba_script.py, which extracts the required data and stores
the data in a JSON document.DocumentationYou can read thecomplete documentationfor an extensive coverage on the background behind Scrapple, a thorough
explanation on the Scrapple package implementation and a complete
coverage of tutorials on how to use Scrapple to run your scraper/crawler
jobs.AuthorsScrapple is maintained byAlex MathewandHarish Balakrishnan.History0.3.0 - 2016-09-23Set up table scraping parameters and executionFix json configuration generation0.2.6 - 2015-11-27Edit requirements0.2.5 - 2015-05-28Add levels argument for genconfig command, to create crawler config files for a specific depth0.2.4 - 2015-04-13Update documentationMinor fixes0.2.3 - 2015-03-11Include implementation to use csv as the output format0.2.2 - 2015-02-22Fix bug in generate script template0.2.1 - 2015-02-21Update tests0.2.0 - 2015-02-20Include implementation forscrapple runandscrapple generatefor crawlersModify web interface for editing scraper config filesRevise skeleton configuration files0.1.1 - 2015-02-10Release on PyPI with revisionsInclude web interface for editing scraper config filesModified implementations of certain functions0.1.0 - 2015-02-04First release on PyPI