BeautifulSoup vs. real-world HTML comments

Wed Apr 4 14:48:32 EDT 2007

Carl Banks wrote:
> On Apr 4, 2:08 pm, John Nagle <n... at animats.com> wrote:
>>     The syntax that browsers understand as HTML comments is much less
>> restrictive than what BeautifulSoup understands.  I keep running into
>> sites with formally incorrect HTML comments which are parsed happily
>> by browsers.  Here's yet another example, this one from
>> "http://www.webdirectory.com".  The page starts like this:
>>
>>         <!Hello there! Welcome to The Environment Directory!>
>>         <!Not too much exciting HTML code here but it does the job! >
>>         <!See ya, - JD >
>>
>>         <HTML><HEAD>
>>         <TITLE>Environment Web Directory</TITLE>
>>
>> Those are, of course, invalid HTML comments. But Firefox, IE, etc. handle them
>> without problems.
>>
>> BeautifulSoup can't parse this page usefully at all.
>> It treats the entire page as a text chunk.  It's actually
>> HTMLParser that parses comments, so this is really an HTMLParser
>> level problem.
> 
> Google for a program called "tidy".  Install it, and run it as a
> filter on any HTML you download.  "tidy" has invested in it quite a
> bit of work understanding common bad HTML and how browsers deal with
> it.  It would be pointless to duplicate that work in the Python
> standard library; let HTMLParser be small and tight, and outsource the
> handling of floozy input to a dedicated program.
> 
> 
eGenix have produced the mxTidy library that handily incorporates these 
features in a way that makes them easy for Python programmers to use.

regards
  Steve
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