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Web Scraping Framework

Grab

What is Grab?

Grab is a python web scraping framework. Grab provides a number of helpful methods to perform network requests, scrape web sites and process the scraped content:

• Automatic cookies (session) support
• HTTP and SOCKS proxy with/without authorization
• Keep-Alive support
• IDN support
• Tools to work with web forms
• Easy multipart file uploading
• Flexible customization of HTTP requests
• Automatic charset detection
• Powerful API to extract data from DOM tree of HTML documents with XPATH queries
• Asynchronous API to make thousands of simultaneous queries. This part of library called Spider. See list of spider fetures below.
• Python 3 ready

Spider is a framework for writing web-site scrapers. Features:

• Rules and conventions to organize the request/parse logic in separate blocks of codes
• Multiple parallel network requests
• Automatic processing of network errors (failed tasks go back to task queue)
• You can create network requests and parse responses with Grab API (see above)
• HTTP proxy support
• Caching network results in permanent storage
• Different backends for task queue (in-memory, redis, mongodb)
• Tools to debug and collect statistics

Grab Example

import logging

from grab import Grab

logging.basicConfig(level=logging.DEBUG)

g = Grab()

g.go('https://github.com/login')
g.doc.set_input('login', '****')
g.doc.set_input('password', '****')
g.doc.submit()

g.doc.save('/tmp/x.html')

g.doc('//ul[@id="user-links"]//button[contains(@class, "signout")]').assert_exists()

home_url = g.doc('//a[contains(@class, "header-nav-link name")]/@href').text()
repo_url = home_url + '?tab=repositories'

g.go(repo_url)

for elem in g.doc.select('//h3[@class="repo-list-name"]/a'):
    print('%s: %s' % (elem.text(),
                      g.make_url_absolute(elem.attr('href'))))

Grab::Spider Example

import logging

from grab.spider import Spider, Task

logging.basicConfig(level=logging.DEBUG)


class ExampleSpider(Spider):
    def task_generator(self):
        for lang in 'python', 'ruby', 'perl':
            url = 'https://www.google.com/search?q=%s' % lang
            yield Task('search', url=url, lang=lang)

    def task_search(self, grab, task):
        print('%s: %s' % (task.lang,
                          grab.doc('//div[@class="s"]//cite').text()))


bot = ExampleSpider(thread_number=2)
bot.run()

Installation

$ pip install -U grab

See details about installing Grab on different platforms here http://docs.grablib.org/en/latest/usage/installation.html

Documentation and Help

Documentation: http://docs.grablib.org/en/latest/

Mailing list (mostly russian): http://groups.google.com/group/python-grab/

Contribution

To report a bug please use GitHub issue tracker: https://github.com/lorien/grab/issues

If you want to develop new feature in Grab please use issue tracker to describe what you want to do or contact me at [email protected]