HTML entity fixer

This blog post is 17 years old! Most likely, its content is outdated. Especially if it's technical.

Here's a little program I wrote recently to fix incorrectly defined characters into HTML entities. For example, this is incorrect:

<b>Bärs &amp; Öl</b>

But this is correct:

<b>B&amp;auml;rs &amp;amp; &amp;Ouml;l</b>

To demonstrate I have set up a little test page here so that you can test to convert your impure HTML content.
Run test program

Here's the source code for the program:

from htmlentitydefs import entitydefs

entitydefs_inverted = {}
for k,v in entitydefs.items():
   entitydefs_inverted[v] = k

_badchars_regex = re.compile('|'.join(entitydefs.values()))
_been_fixed_regex = re.compile('&amp;\w+;|&amp;#[0-9]+;')
def html_entity_fixer(text, skipchars=[], extra_careful=1):

   # if extra_careful we don't attempt to do anything to
   # the string if it might have been converted already.
   if extra_careful and _been_fixed_regex.findall(text):
       return text

   if type(skipchars) == type('s'):
       skipchars = [skipchars]

   keyholder= {}
   for x in _badchars_regex.findall(text):
       if x not in skipchars:
           keyholder[x] = 1
   text = text.replace('&amp;','&amp;amp;')
   text = text.replace('\x80', '&amp;#8364;')
   for each in keyholder.keys():
       if each == '&amp;':
           continue

       better = entitydefs_inverted[each]
       if not better.startswith('&amp;#'):
           better = '&amp;%s;'%entitydefs_inverted[each]

       text = text.replace(each, better)
   return text

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Comments

Harald Armin Massa 26 November 2004 Reply

Peter,

I learned that using Umlauts may be quite correct by setting the encoding to latin-1 (aka ISO something) or UTF-8 ... esp. with xhtml.

So the only BAD chars will be <,> and & ...

Harald

James Harlow 26 November 2004 Reply

Harald - you're correct (iso8859-1, by the way) - but making sure that the declared encoding of the document is the actual encoding of the document is not trivial. It's better to encode, if you can.

http://www.xml.com/pub/a/2004/07/21/dive.html explains it much better than I can. :-)

Bogdano 24 January 2005 Reply

It's not better to use entitytdefs.iteritems() instead of .items()?

Peter 24 January 2005 Reply

Actually not. iteritems() is only faster than items() when the size of the dictionnary exceeds 1000 if the elements in the dict are small. I know this because I've done some benchmarking.

Gary 04 March 2005 Reply

Peter, thanks for publishing this on the web. You think it'd be easier or more intuitive to html-escape characters in python. Have you thought about submitting your code for inclusion as a global module?

Because I'm such a forward thinker with a knack for coming up with unique names... I think...

from htmlescape import *

:D

Rafael Zanella 31 March 2007 Reply

Mine lame version:

#/usr/bin/python

import sys
import os

#http://www.asciitable.com/
#http://www.w3schools.com/tags/ref_entities.asp

#DICT { char : HTML entity }
dicionario = {
    # ISO 8859-1 Character Entities
    'À' : "À", 'Á' : "Á", 'Â' : "Â", 'Ã' : "Ã", 'Ä' : "Ä", 'Å' : "Å",
    'Æ' : "Æ", 'Ç' : "Ç",
    'È' : "È", 'É' : "É", 'Ê' : "Ê", 'Ë' : "Ë",
    'Ì' : "Ì", 'Í' : "Í", 'Î' : "Î", 'Ï' : "Ï",
    'Ð' : "Ð", 'Ñ' : "Ñ",
    'Ò' : "Ò", 'Ó' : "Ó", 'Ô' : "Ô", 'Õ' : "Õ", 'Ö' : "Ö", 'Ø' : "Ø",
    'Ù' : "Ù", 'Ú' : "Ú", 'Û' : "Û", 'Ü' : "Ü",
    'Ý' : "Ý",
    'Þ' : "Þ", 'ß' : "ß",
    'à' : "à", 'á' : "á", 'â' : "â", 'ã' : "ã", 'ä' : "ä", 'å' : "å",
    'æ' : "æ", 'ç' : "ç",
    'è' : "è", 'é' : "é", 'ê' : "ê", 'ë' : "ë",
    'ì' : "ì", 'í' : "í", 'î' : "î", 'ï' : "ï",
    'ð' : "ð", 'ñ' : "ñ",
    'ò' : "ò", 'ó' : "ó", 'ô' : "ô", 'õ' : "õ", 'ö' : "ö", 'ø' : "ø",
    'ù' : "ù", 'ú' : "ú", 'û' : "û", 'ü' : "ü",
    'ý' : "ý", 'þ' : "þ", 'ÿ' : "ÿ",
};

def main ():
    try:
        if (sys.argv[1]):
            originalFile = open(sys.argv[1], "r")
            newFile = open(sys.argv[1] + ".RC", "w");

            while 1:
                #Variables
                read = originalFile.readline();
                strHolder = "";

                if not read:
                    break;

                for char in read: # for i in xrange(len(read) - 1)
                    try:
                        if ( ord(char) > 128):
                            strHolder += dicionario[char];
                        else:
                            strHolder += char;
                    except KeyError: # if the char is extended ASCII but hasn't been included on the dict
                        strHolder += char;
                #End for
                print strHolder; ##scaffolding
                newFile.write(strHolder);
            #End while

            #Close-ups
            originalFile.close();
            newFile.close();
        #end if
    except IndexError:
        print "\n\nModo de uso: toEntities.py <Nome_Do_Arquivo>\n\n"; return 1;
    except IOError:
            print "\n\nArquivo nao pode ser aberto...\n\n"; return 2;
#end main

main();
#EOF

da8 13 January 2009 Reply

Thanks a lot for your Script. You made my day. So far i have been using a homemade script with a self defined lookup table for Ä, Ö, Ü and so on. I am still wondering why python struggles with this so often required feature. I guess i do not understand the full picture but i liked to have this kind of functionality in the modules concerning XML/HTML. Kind regards, da8

Eduardo 17 February 2009 Reply

http://channel3b.wordpress.com/2007/07/04/how-to-convert-html-entities-to-real-unicode-in-python/

Matt H 22 October 2009 Reply

Hi, Great program. I needed to add one line at the beginning to get it to work:

import re

HTML entity fixer

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