https://github.com/kish1/krawll

Web crawling made easy for Pythonistas. Just supply extractor and terminator functions to this higher-order function and let krawll do the rest.
https://github.com/kish1/krawll

Last synced: 3 months ago
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Web crawling made easy for Pythonistas. Just supply extractor and terminator functions to this higher-order function and let krawll do the rest.

• Host: GitHub
• URL: https://github.com/kish1/krawll
• Owner: kish1
• License: mit
• Created: 2015-05-15T23:33:29.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2017-03-25T04:39:00.000Z (over 7 years ago)
• Last Synced: 2024-05-16T02:42:02.084Z (6 months ago)
• Language: Python
• Homepage:
• Size: 5.86 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• project-awesome - kish1/krawll - Web crawling made easy for Pythonistas. Just supply extractor and terminator functions to this higher-order function and let krawll do the rest. (Python)

README

        
# krawll

Web crawling made easy for Pythonistas. Just supply extractor and terminator functions to this higher-order function and let krawll do the rest.

# How to use krawll

Supply the following to the krawll function:

1. *Extractor* - A function that parses and extracts the required data from the HTML and returns the data as a dictionary.

2. *Terminator* - A function that returns True when the crawler should terminate, False otherwise.

_krawll(cookies, homepage, hostname, extractor, terminator)_

# Example

```python

# heading_extractor: String -> Dict

# GIVEN: a html source tree

# RETURNS: a data structure containing newly extracted data

# an empty list otherwise.

def heading_extractor(html):

	import BeautifulSoup

	soup = BeautifulSoup(html)

	h1s = soup.find_all('h1')

	hits = []

	for tag in h1s:

		str_tag = str(tag)

		if str_tag.startswith('
Breaking News: '):

			hits.append(str(tag.string).split('FLAG: ')[1])

	news = {}

	for hit in hits:

		if not news.has_key(hit):

			news[hit] = 1

	return new


# may_exit: Dict -> Boolean

# GIVEN: a data structure containing the extracted data

# RETURNS: True if the required number of hits have been found, False otherwise.

# This implies that the crawler will terminate when this function returns True.

def may_exit(news):

	return len(news) == 20

	

# never_exit: Dict -> Boolean

# GIVEN: a data structure containing the extracted data

# RETURNS: False. This implies that the crawler will crawl the entire domain.

def never_exit(news):

	return False

import krawll

cookies = {}

home_page = 'http://www.xyznews.com'

host = 'www.xyznews.com'

news_dict = krawll.krawll(cookies, home_page, host, heading_extractor, may_exit)

```