Limnoria/plugins/DDG/plugin.py
Valentin Lorentz 10df0a0dd0 DDG: Rewrite using html.parser.HTMLParser instead of BeautifulSoup.
So we don't depend on an external library.
2020-05-15 21:26:44 +02:00

149 lines
5.9 KiB
Python

###
# Copyright (c) 2014-2017, James Lu <james@overdrivenetworks.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions, and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions, and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the author of this software nor the name of
# contributors to this software may be used to endorse or promote products
# derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###
import functools
from html.parser import HTMLParser
from urllib.parse import urlencode, parse_qs
import supybot.utils as utils
from supybot.commands import *
import supybot.plugins as plugins
import supybot.ircutils as ircutils
import supybot.callbacks as callbacks
import supybot.log as log
try:
from supybot.i18n import PluginInternationalization
_ = PluginInternationalization('DDG')
except ImportError:
# Placeholder that allows to run the plugin on a bot
# without the i18n module
_ = lambda x: x
from .parser import DDGHTMLParser
class DDG(callbacks.Plugin):
"""Searches for results on DuckDuckGo."""
threaded = True
@staticmethod
def _ddgurl(text):
# DuckDuckGo has a 'lite' site free of unparseable JavaScript
# elements, so we'll use that to our advantage!
url = "https://duckduckgo.com/lite?" + urlencode({"q": text})
log.debug("DDG: Using URL %s for search %s", url, text)
real_url, data = utils.web.getUrlTargetAndContent(url)
data = data.decode("utf-8")
parser = DDGHTMLParser()
parser.feed(data)
# Remove "sponsored link" results
return (url, real_url, parser.results)
def search_core(self, text, channel_context=None, max_results=None, show_snippet=None):
"""
Core results fetcher for the DDG plugin. Other plugins can call this as well via
irc.getCallback('DDG').search_core(...)
"""
if show_snippet is None:
# Note: don't use ternary here, or the registry value will override any False
# settings given to the function directly.
show_snippet = self.registryValue("showSnippet", channel_context)
maxr = max_results or self.registryValue("maxResults", channel_context)
self.log.debug('DDG: got %s for max results', maxr)
# In a nutshell, the 'lite' site puts all of its usable content
# into tables. This does mean that headings, result snippets and
# everything else are all using the same tag (<td>), so parsing is
# still somewhat tricky.
results = []
url, real_url, raw_results = self._ddgurl(text)
if real_url != url:
# We received a redirect, likely from something like a !bang request.
# Don't bother parsing the target page, as it probably won't work anyways.
return [('', '', real_url)]
for t in raw_results:
if self.registryValue("showsnippet", channel_context):
snippet = t.snippet.strip()
else:
snippet = ''
title = t.title.strip()
origlink = link = t.link
# As of 2017-01-20, some links on DuckDuckGo's site are shown going through
# a redirect service. The links are in the format "/l/?kh=-1&uddg=https%3A%2F%2Fduckduckgo.com%2F"
# instead of simply being "https://duckduckgo.com". So, we decode these links here.
if link.startswith('/l/'):
linkparse = utils.web.urlparse(link)
try:
link = parse_qs(linkparse.query)['uddg'][0]
except KeyError:
# No link was given here, skip.
continue
except IndexError:
self.log.exception("DDG: failed to expand redirected result URL %s", origlink)
continue
else:
self.log.debug("DDG: expanded result URL from %s to %s", origlink, link)
# Return a list of tuples in the form (link title, snippet text, link)
results.append((title, snippet, link))
return results[:maxr]
@wrap(['text'])
def search(self, irc, msg, args, text):
"""<text>
Searches for <text> on DuckDuckGo's web search."""
results = self.search_core(text, msg.args[0])
if not results:
irc.error("No results found.")
else:
strings = []
for r in results:
if not r[0]:
# This result has no title, so it's likely a redirect from !bang.
strings.append(format("See %u", r[2]))
else:
strings.append(format("%s - %s %u", ircutils.bold(r[0]), r[1], r[2]))
irc.reply(', '.join(strings))
Class = DDG
# vim:set shiftwidth=4 softtabstop=4 expandtab textwidth=79: