def __init__(self, indexTableName=INDEX_TABLE, linksTableName=LINKS_TABLE):
"""
Initialize the database and cursors
"""
# Patterns to find end of main wiki article
self.reference_pattern = re.compile('=+\s?References\s?=+')
self.extlink_pattern = re.compile('=+\s?External links\s?=+')
# Initialize the needed database connections and create a new indexTable if necessary
self.linksModel = LinksModel(linksTable=linksTableName)
self.indexModel = IndexModel(indexTable=indexTableName)
# Stats counters
self.total_articles = 0
self.total_links = 0
class ArticleLinkExtractor:
"""
Class to read through a MySQL index of wiki articles, extract a list of all links contained, and store in new indexTable
"""
def __init__(self, indexTableName=INDEX_TABLE, linksTableName=LINKS_TABLE):
"""
Initialize the database and cursors
"""
# Patterns to find end of main wiki article
self.reference_pattern = re.compile('=+\s?References\s?=+')
self.extlink_pattern = re.compile('=+\s?External links\s?=+')
# Initialize the needed database connections and create a new indexTable if necessary
self.linksModel = LinksModel(linksTable=linksTableName)
self.indexModel = IndexModel(indexTable=indexTableName)
# Stats counters
self.total_articles = 0
self.total_links = 0
def extractLinks(self, wikiPage):
"""
Takes a WikiPage object as an argument
Returns a list of all valid links found within the current article
"""
text = wikiPage.text
links = set()
# End string at Reference or External Links section if possible
reference_match = self.reference_pattern.search(text)
if reference_match:
text = text[:reference_match.start()]
else:
extlink_match = self.extlink_pattern.search(text)
if extlink_match:
text = text[:extlink_match.start()]
# Start iteratively hunting for links (items surrounded by double square brackets)
link_start = text.find("[[")
while link_start != -1:
# Ignore links that start with 'File:'
if text[link_start + 2: link_start + 7] == "File:":
link_end = link_start
#TODO: Check for "Category:" also
else:
# Find first matching closing bracket pair
link_end = text.find("]]", link_start)
new_link = text[link_start + 2: link_end]
# Remove alternate display text
alt_text = new_link.find("|")
if alt_text > 0:
new_link = new_link[:alt_text]
# Remove category display text
category_text = new_link.find("#")
if category_text > 0:
new_link = new_link[:category_text]
# Add new link to current list of links
links.add(new_link.strip())
# Edit string to remove previous link
text = text[link_end + 2:]
link_start = text.find("[[")
return links
def parseAllNewArticles(self):
"""
Determine last index row ID added to DB
Iterate through all articles starting from this row in the indexTable
Create a WikiPage from the row and pass to extractLinks(WikiPage)
Store all links found in linksTable
"""
# Find number of possible objects in DB
max_count = self.indexModel.getMaxRowId()
# Determine last article ID added to DB
last_id = self.linksModel.getMaxIndexId()
if last_id > 0:
curr_row = last_id + 1
print "Indexing all articles starting from row %d in indexTable %s" % (curr_row, self.indexModel.indexTable)
else:
curr_row = 1
print "No previous articles found in linksTable %s, adding all new articles from the beginning." \
% self.linksModel.linksTable
# Fetch every possible row in the database
while curr_row <= max_count:
wiki_page = self.indexModel.getWikiPage(curr_row)
if wiki_page:
links = self.extractLinks(wiki_page)
self.total_articles += 1
self.total_links += len(links)
# Store links in links_from indexTable
self.linksModel.storeLinks(curr_row, links)
print "Links within %s (rowid %d): %d" % (wiki_page.title, curr_row, len(links))
curr_row += 1
def exitHandler(self):
"""
Called when program is killed
"""
self.linksModel.closeTable()
self.indexModel.closeTable()
# Show off the output
print ""
print "ArticleLinkExtractor closing. Parsed the following new articles:"
if self.total_articles > 0:
print "Total articles: %d" % self.total_articles
print "Total links: %d" % self.total_links
print "Avg links/art: %f" % (1.0 * self.total_links / self.total_articles)
else:
print "No new articles added."
