HTML tag validation in Python

Question

I want to validate HTML tag to determine whether it is valid HTML or not.

I tried the following code.

 def must_have_proper_htmltag(self,filename):
        """

        :param filename:
        :return:
        """
        print(filename)
        return bool(BeautifulSoup(filename, 'html.parser').find())

        '''Beautiful soup is library function to pull HTML or XML
           html.parser is for choosing html doc and find() for
           checking occuranc'''
`htmltags='<html><head><title>Test</title></head>''<body><h1>Parse me!</h1>
 </body></html>'
nohtmltag = '<html><head><title>Test</title></head>''<body><h1>Parse me!'
print('html checkers:-',qc.must_have_proper_htmltag(htmltag))
print('html checkers:-',qc.must_have_proper_htmltag(nohtmltag))

This function check whether there is HTML tag or not..it doesn’t validate whether the HTML tag is right or not.

How can I validate HTML tag? I want output that HTML tag one is True other one is False

Asked By: Arpan Ghimire

||

Source

Answer 1

While not an exact match to your requirement, maybe it’s easier to leverage work others have already done. For example:

It does not check for single tags but for the whole of the HTML to be correct, which is apparently what you’re after.

Possibly this approach may help you as well:

import HTMLParser
import urllib
import sys
import urlparse

##################################################
# config

base_url = 'http://foo.com/bill_reid/'
depth = 100

w3c_validator = 'http://validator.w3.org/'

##################################################
# classes and functions

# HTML parser class
class parseLinks(HTMLParser.HTMLParser):
    def handle_starttag(self, tag, attrs):
        if tag == 'a':
            for name,value in attrs:
                if name == 'href':
                    url = url_normalize(value)
                    if url != "" and not(l.has_key(url)):
                        l[url] = True;

# HTML parsing function (use the class)
def parse_links(url):
    try:
        lParser = parseLinks()
        lParser.feed(urllib.urlopen(url).read())
        lParser.close()
    except:
        pass

# clean/normalize/reject url
def url_normalize(url):
    url= url.strip()

    # check it's not an email address
    if url.startswith('mailto:'):
        return ""

    # remove any anchor
    url = url.partition('#')[0]

    # check it's not an outside-of-the-tree link
    url = urlparse.urljoin(current_url, url)
    if not(url.startswith(base_url)):
        return ""

    # check it's an HTML page
    if urllib.urlopen(url).info().gettype() != 'text/html':
        return ""

    return url

# W3C validation
def url_w3c_validate(url):
    return urllib.urlopen(w3c_validator + 'check?uri=' + url).info().getheader('x-w3c-validator-status') == 'Valid'

##################################################
# main
##################################################
l = {base_url: True}
l_error = []
n = 0
for i in range(depth):
    for url in l.copy():
        if l[url]:
            n += 1
            current_url = url
            print n,
            print "-",
            print current_url,

            print " parsing...",
            parse_links(url)
            print "done -",

            print "validating...",
            is_valid = url_w3c_validate(url)
            print "done ->",
            if is_valid:
                print "Valid"
            else:
                l_error.append(url)
                print "Invalid"

            l[url] = False

#report
print """
-------------------------------------
URLs parsed: %d
URLS with invalid HTML: %d""" % (len(l), len(l_error))

for url in l_error:
    print url

Answered By: herrbischoff

Answer 2

You can validate it using w3c validator

from py_w3c.validators.html.validator import HTMLValidator

def must_have_proper_htmltag(self,filename):
    """

    :param filename:
    :return:
    """
    print(filename)
    html_validator = HTMLValidator()
    html_validator.validate_fragment(filename)
    if not html_validator.errors:
        '''Where there is no error it return empty list'''
        return True
    else:
        return False

print('html checkers:-',qc.must_have_proper_htmltag('<!DOCTYPE html><html>
<head><title>Test</title></head>''<body><h1>Parse me!</h1></body></html>'))

Answered By: Awesome

HTML tag validation in Python

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