How to find and extract link from webpage? - python

I have website , e.g http://site.com
I would like fetch main page and extract only links that match the regular expression, e.g .*somepage.*
The format of links in html code can be:
url
url
url
I need the output format:
http://site.com/my-somepage
http://site.com/my-somepage.html
http://site.com/my-somepage.htm
Output url must contain domain name always.
What is the fast python solution for this?

You could use lxml.html:
from lxml import html
url = "http://site.com"
doc = html.parse(url).getroot() # download & parse webpage
doc.make_links_absolute(url)
for element, attribute, link, _ in doc.iterlinks():
if (attribute == 'href' and element.tag == 'a' and
'somepage' in link): # or e.g., re.search('somepage', link)
print(link)
Or the same using beautifulsoup4:
import re
try:
from urllib2 import urlopen
from urlparse import urljoin
except ImportError: # Python 3
from urllib.parse import urljoin
from urllib.request import urlopen
from bs4 import BeautifulSoup, SoupStrainer # pip install beautifulsoup4
url = "http://site.com"
only_links = SoupStrainer('a', href=re.compile('somepage'))
soup = BeautifulSoup(urlopen(url), parse_only=only_links)
urls = [urljoin(url, a['href']) for a in soup(only_links)]
print("\n".join(urls))

Use an HTML Parsing module, like BeautifulSoup.
Some code(only some):
from bs4 import BeautifulSoup
import re
html = '''url
url
url'''
soup = BeautifulSoup(html)
links = soup.find_all('a',{'href':re.compile('.*somepage.*')})
for link in links:
print link['href']
Output:
http://site.com/my-somepage
/my-somepage.html
my-somepage.htm
You should be able to get the format you want from this much data...

Scrapy is the simplest way to do what you want. There is actually link extracting mechanism built-in.
Let me know if you need help with writing the spider to crawl links.
Please, also see:
How do I use the Python Scrapy module to list all the URLs from my website?
Scrapy tutorial

Related

I need to get specific data from a website using inspect element

I'm new to Python and I'm struggling to find a solution or a way to do the following thing. I need 2 things from a website that I can get from inspect element: the link to the .m3u8 file which can be found in the html (Elements tab) of the website and a link to a .ts file (it doesn't matter which one) from the Network tab. Does anybody know how to do this? Thanks in advance!
Use BS4 and requests:
import requests
from bs4 import BeautifulSoup
URL = 'https://stackoverflow.com/questions/64828046/'
page = requests.get(URL)
soup = BeautifulSoup(page.content, 'html.parser')
results = soup.find(id='question-header')
print(results)
from urllib.request import urlopen
import lxml.html
connection = urlopen('http://yourwebsite')
dom = lxml.html.fromstring(connection.read())
for link in dom.xpath('//a/#href'):
if link.endswith(".m3u8") or link.endwith(".ts"):
print(link)
you can use other if conditions to check whether something is in the link, like:
if "m3u8" in link:
print(link)

Using Beautiful Soup to Scrape content encoded in unicode? [duplicate]

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How can I retrieve the links of a webpage and copy the url address of the links using Python?
Here's a short snippet using the SoupStrainer class in BeautifulSoup:
import httplib2
from bs4 import BeautifulSoup, SoupStrainer
http = httplib2.Http()
status, response = http.request('http://www.nytimes.com')
for link in BeautifulSoup(response, parse_only=SoupStrainer('a')):
if link.has_attr('href'):
print(link['href'])
The BeautifulSoup documentation is actually quite good, and covers a number of typical scenarios:
https://www.crummy.com/software/BeautifulSoup/bs4/doc/
Edit: Note that I used the SoupStrainer class because it's a bit more efficient (memory and speed wise), if you know what you're parsing in advance.
For completeness sake, the BeautifulSoup 4 version, making use of the encoding supplied by the server as well:
from bs4 import BeautifulSoup
import urllib.request
parser = 'html.parser' # or 'lxml' (preferred) or 'html5lib', if installed
resp = urllib.request.urlopen("http://www.gpsbasecamp.com/national-parks")
soup = BeautifulSoup(resp, parser, from_encoding=resp.info().get_param('charset'))
for link in soup.find_all('a', href=True):
print(link['href'])
or the Python 2 version:
from bs4 import BeautifulSoup
import urllib2
parser = 'html.parser' # or 'lxml' (preferred) or 'html5lib', if installed
resp = urllib2.urlopen("http://www.gpsbasecamp.com/national-parks")
soup = BeautifulSoup(resp, parser, from_encoding=resp.info().getparam('charset'))
for link in soup.find_all('a', href=True):
print link['href']
and a version using the requests library, which as written will work in both Python 2 and 3:
from bs4 import BeautifulSoup
from bs4.dammit import EncodingDetector
import requests
parser = 'html.parser' # or 'lxml' (preferred) or 'html5lib', if installed
resp = requests.get("http://www.gpsbasecamp.com/national-parks")
http_encoding = resp.encoding if 'charset' in resp.headers.get('content-type', '').lower() else None
html_encoding = EncodingDetector.find_declared_encoding(resp.content, is_html=True)
encoding = html_encoding or http_encoding
soup = BeautifulSoup(resp.content, parser, from_encoding=encoding)
for link in soup.find_all('a', href=True):
print(link['href'])
The soup.find_all('a', href=True) call finds all <a> elements that have an href attribute; elements without the attribute are skipped.
BeautifulSoup 3 stopped development in March 2012; new projects really should use BeautifulSoup 4, always.
Note that you should leave decoding the HTML from bytes to BeautifulSoup. You can inform BeautifulSoup of the characterset found in the HTTP response headers to assist in decoding, but this can be wrong and conflicting with a <meta> header info found in the HTML itself, which is why the above uses the BeautifulSoup internal class method EncodingDetector.find_declared_encoding() to make sure that such embedded encoding hints win over a misconfigured server.
With requests, the response.encoding attribute defaults to Latin-1 if the response has a text/* mimetype, even if no characterset was returned. This is consistent with the HTTP RFCs but painful when used with HTML parsing, so you should ignore that attribute when no charset is set in the Content-Type header.
Others have recommended BeautifulSoup, but it's much better to use lxml. Despite its name, it is also for parsing and scraping HTML. It's much, much faster than BeautifulSoup, and it even handles "broken" HTML better than BeautifulSoup (their claim to fame). It has a compatibility API for BeautifulSoup too if you don't want to learn the lxml API.
Ian Blicking agrees.
There's no reason to use BeautifulSoup anymore, unless you're on Google App Engine or something where anything not purely Python isn't allowed.
lxml.html also supports CSS3 selectors so this sort of thing is trivial.
An example with lxml and xpath would look like this:
import urllib
import lxml.html
connection = urllib.urlopen('http://www.nytimes.com')
dom = lxml.html.fromstring(connection.read())
for link in dom.xpath('//a/#href'): # select the url in href for all a tags(links)
print link
import urllib2
import BeautifulSoup
request = urllib2.Request("http://www.gpsbasecamp.com/national-parks")
response = urllib2.urlopen(request)
soup = BeautifulSoup.BeautifulSoup(response)
for a in soup.findAll('a'):
if 'national-park' in a['href']:
print 'found a url with national-park in the link'
The following code is to retrieve all the links available in a webpage using urllib2 and BeautifulSoup4:
import urllib2
from bs4 import BeautifulSoup
url = urllib2.urlopen("http://www.espncricinfo.com/").read()
soup = BeautifulSoup(url)
for line in soup.find_all('a'):
print(line.get('href'))
Links can be within a variety of attributes so you could pass a list of those attributes to select.
For example, with src and href attributes (here I am using the starts with ^ operator to specify that either of these attributes values starts with http):
from bs4 import BeautifulSoup as bs
import requests
r = requests.get('https://stackoverflow.com/')
soup = bs(r.content, 'lxml')
links = [item['href'] if item.get('href') is not None else item['src'] for item in soup.select('[href^="http"], [src^="http"]') ]
print(links)
Attribute = value selectors
[attr^=value]
Represents elements with an attribute name of attr whose value is prefixed (preceded) by value.
There are also the commonly used $ (ends with) and * (contains) operators. For a full syntax list see the link above.
Under the hood BeautifulSoup now uses lxml. Requests, lxml & list comprehensions makes a killer combo.
import requests
import lxml.html
dom = lxml.html.fromstring(requests.get('http://www.nytimes.com').content)
[x for x in dom.xpath('//a/#href') if '//' in x and 'nytimes.com' not in x]
In the list comp, the "if '//' and 'url.com' not in x" is a simple method to scrub the url list of the sites 'internal' navigation urls, etc.
just for getting the links, without B.soup and regex:
import urllib2
url="http://www.somewhere.com"
page=urllib2.urlopen(url)
data=page.read().split("</a>")
tag="<a href=\""
endtag="\">"
for item in data:
if "<a href" in item:
try:
ind = item.index(tag)
item=item[ind+len(tag):]
end=item.index(endtag)
except: pass
else:
print item[:end]
for more complex operations, of course BSoup is still preferred.
This script does what your looking for, But also resolves the relative links to absolute links.
import urllib
import lxml.html
import urlparse
def get_dom(url):
connection = urllib.urlopen(url)
return lxml.html.fromstring(connection.read())
def get_links(url):
return resolve_links((link for link in get_dom(url).xpath('//a/#href')))
def guess_root(links):
for link in links:
if link.startswith('http'):
parsed_link = urlparse.urlparse(link)
scheme = parsed_link.scheme + '://'
netloc = parsed_link.netloc
return scheme + netloc
def resolve_links(links):
root = guess_root(links)
for link in links:
if not link.startswith('http'):
link = urlparse.urljoin(root, link)
yield link
for link in get_links('http://www.google.com'):
print link
To find all the links, we will in this example use the urllib2 module together
with the re.module
*One of the most powerful function in the re module is "re.findall()".
While re.search() is used to find the first match for a pattern, re.findall() finds all
the matches and returns them as a list of strings, with each string representing one match*
import urllib2
import re
#connect to a URL
website = urllib2.urlopen(url)
#read html code
html = website.read()
#use re.findall to get all the links
links = re.findall('"((http|ftp)s?://.*?)"', html)
print links
Why not use regular expressions:
import urllib2
import re
url = "http://www.somewhere.com"
page = urllib2.urlopen(url)
page = page.read()
links = re.findall(r"<a.*?\s*href=\"(.*?)\".*?>(.*?)</a>", page)
for link in links:
print('href: %s, HTML text: %s' % (link[0], link[1]))
Here's an example using #ars accepted answer and the BeautifulSoup4, requests, and wget modules to handle the downloads.
import requests
import wget
import os
from bs4 import BeautifulSoup, SoupStrainer
url = 'https://archive.ics.uci.edu/ml/machine-learning-databases/eeg-mld/eeg_full/'
file_type = '.tar.gz'
response = requests.get(url)
for link in BeautifulSoup(response.content, 'html.parser', parse_only=SoupStrainer('a')):
if link.has_attr('href'):
if file_type in link['href']:
full_path = url + link['href']
wget.download(full_path)
I found the answer by #Blairg23 working , after the following correction (covering the scenario where it failed to work correctly):
for link in BeautifulSoup(response.content, 'html.parser', parse_only=SoupStrainer('a')):
if link.has_attr('href'):
if file_type in link['href']:
full_path =urlparse.urljoin(url , link['href']) #module urlparse need to be imported
wget.download(full_path)
For Python 3:
urllib.parse.urljoin has to be used in order to obtain the full URL instead.
BeatifulSoup's own parser can be slow. It might be more feasible to use lxml which is capable of parsing directly from a URL (with some limitations mentioned below).
import lxml.html
doc = lxml.html.parse(url)
links = doc.xpath('//a[#href]')
for link in links:
print link.attrib['href']
The code above will return the links as is, and in most cases they would be relative links or absolute from the site root. Since my use case was to only extract a certain type of links, below is a version that converts the links to full URLs and which optionally accepts a glob pattern like *.mp3. It won't handle single and double dots in the relative paths though, but so far I didn't have the need for it. If you need to parse URL fragments containing ../ or ./ then urlparse.urljoin might come in handy.
NOTE: Direct lxml url parsing doesn't handle loading from https and doesn't do redirects, so for this reason the version below is using urllib2 + lxml.
#!/usr/bin/env python
import sys
import urllib2
import urlparse
import lxml.html
import fnmatch
try:
import urltools as urltools
except ImportError:
sys.stderr.write('To normalize URLs run: `pip install urltools --user`')
urltools = None
def get_host(url):
p = urlparse.urlparse(url)
return "{}://{}".format(p.scheme, p.netloc)
if __name__ == '__main__':
url = sys.argv[1]
host = get_host(url)
glob_patt = len(sys.argv) > 2 and sys.argv[2] or '*'
doc = lxml.html.parse(urllib2.urlopen(url))
links = doc.xpath('//a[#href]')
for link in links:
href = link.attrib['href']
if fnmatch.fnmatch(href, glob_patt):
if not href.startswith(('http://', 'https://' 'ftp://')):
if href.startswith('/'):
href = host + href
else:
parent_url = url.rsplit('/', 1)[0]
href = urlparse.urljoin(parent_url, href)
if urltools:
href = urltools.normalize(href)
print href
The usage is as follows:
getlinks.py http://stackoverflow.com/a/37758066/191246
getlinks.py http://stackoverflow.com/a/37758066/191246 "*users*"
getlinks.py http://fakedomain.mu/somepage.html "*.mp3"
There can be many duplicate links together with both external and internal links. To differentiate between the two and just get unique links using sets:
# Python 3.
import urllib
from bs4 import BeautifulSoup
url = "http://www.espncricinfo.com/"
resp = urllib.request.urlopen(url)
# Get server encoding per recommendation of Martijn Pieters.
soup = BeautifulSoup(resp, from_encoding=resp.info().get_param('charset'))
external_links = set()
internal_links = set()
for line in soup.find_all('a'):
link = line.get('href')
if not link:
continue
if link.startswith('http'):
external_links.add(link)
else:
internal_links.add(link)
# Depending on usage, full internal links may be preferred.
full_internal_links = {
urllib.parse.urljoin(url, internal_link)
for internal_link in internal_links
}
# Print all unique external and full internal links.
for link in external_links.union(full_internal_links):
print(link)
import urllib2
from bs4 import BeautifulSoup
a=urllib2.urlopen('http://dir.yahoo.com')
code=a.read()
soup=BeautifulSoup(code)
links=soup.findAll("a")
#To get href part alone
print links[0].attrs['href']

Reading in Content From URLS in a File

I'm trying to get other subset URLs from a main URL. However,as I print to see if I get the content, I noticed that I am only getting the HTML, not the URLs within it.
import urllib
file = 'http://example.com'
with urllib.request.urlopen(file) as url:
collection = url.read().decode('UTF-8')
I think this is what you are looking for.
You can use beautiful soup library of python and this code should work with python3
import urllib
from urllib.request import urlopen
from bs4 import BeautifulSoup
def get_all_urls(url):
open = urlopen(url)
url_html = BeautifulSoup(open, 'html.parser')
for link in url_html.find_all('a'):
links = str(link.get('href'))
if links.startswith('http'):
print(links)
else:
print(url + str(links))
get_all_urls('url.com')

Suitable javascript parser to be used with urlopen

I am trying the following:
from urllib2 import urlopen
from BeautifulSoup import BeautifulSoup
url = 'http://search.wcad.org/Property-Detail?PropertyQuickRefID=R000017&PartyQuickRefID=O0532572'
soup = BeautifulSoup(urlopen(url).read())
print soup
The print statement displays very complicated text structure and it is difficult to extract variables. What is the better way to extract variables like Legal Description
You don't need to parse JavaScript to get the "Legal Description" value - you need to parse HTML and BeautifulSoup HTML parser can do the job. Locate the td element "by 'Legal Description' text" and then get the next td element:
soup.find("td", text="Legal Description").find_next_sibling("td").get_text()
Note: you are using BeautifulSoup version 3 - it is very outdated and not maintained - switch to the 4th version:
pip install beautifulsoup4
And change your import from:
from BeautifulSoup import BeautifulSoup
to:
from bs4 import BeautifulSoup
Though you can do this with urllib2 I would recommend to use requests.
The id is unique for each field, so you can get the text directly by finding the element using id.
import requests
from bs4 import BeautifulSoup
url = "http://search.wcad.org/Property-Detail?PropertyQuickRefID=R000017&PartyQuickRefID=O0532572"
html = requests.get(url)
soup = BeautifulSoup(html.text, "lxml")
text = soup.find("td", id="dnn_ctr1460_View_tdGILegalDescription").get_text()
print(text)
NOTE: I've used Beautifulsoup version 4. To install it use this command - pip install bs4.

How to extract all urls having .html at the end?

from bs4 import BeautifulSoup
import requests
r = requests.get("xxx")
soup = BeautifulSoup(r.content)
for link in soup.find_all('html'):
print link
This not working for me someone can help?
for link in soup.find_all('a'):
if '.html' in link['href']:
print link
you might want to use regular expressions and search for "href" attributes. Something like this to help you get started. Assuming you are searching all href attributes
import re
from urllib2 import urlopen
from bs4 import BeautifulSoup
tags = soup.find_all(href = re.compile(r"\.html$"))
tags variable will be a list of all html tags whose href attribute ends in .html. Now, you can loop through tags and extract the href

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