Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
On 2008-01-23, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi, I am looking for a HTML parser who can parse a given page into a DOM tree, and can reconstruct the exact original html sources. Why not keep a copy of the original data instead? That would be VERY MUCH SIMPLER than trying to reconstruct a parsed tree back to original source text. sincerely, Albert -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
On Jan 23, 7:39 pm, A.T.Hofkamp [EMAIL PROTECTED] wrote: On 2008-01-23, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi, I am looking for a HTML parser who can parse a given page into a DOM tree, and can reconstruct the exact original html sources. Why not keep a copy of the original data instead? That would be VERY MUCH SIMPLER than trying to reconstruct a parsed tree back to original source text. sincerely, Albert Thank u for your reply. but what I really need is the mapping between each DOM nodes and the corresponding original source segment. -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
On 23 Jan, 14:20, kliu [EMAIL PROTECTED] wrote: Thank u for your reply. but what I really need is the mapping between each DOM nodes and the corresponding original source segment. At the risk of promoting unfashionable DOM technologies, you can at least serialise fragments of the DOM in libxml2dom [1]: import libxml2dom d = libxml2dom.parseURI(http://www.diveintopython.org/;, html=1) print d.xpath(//p)[7].toString() Storage and retrieval of the original line and offset information may be supported by libxml2, but such information isn't exposed by libxml2dom. Paul [1] http://www.python.org/pypi/libxml2dom -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
Hi, kliu wrote: what I really need is the mapping between each DOM nodes and the corresponding original source segment. I don't think that will be easy to achieve. You could get away with a parser that provides access to the position of an element in the source, and then map changes back into the document. But that won't work well in the case where the parser inserts or deletes content to fix up the structure. Anyway, the normal focus of broken HTML parsing is in fixing the source document, not in writing out a broken document. Maybe we could help you better if you explained what your actual intention is? Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
On 2008-01-23, kliu [EMAIL PROTECTED] wrote: On Jan 23, 7:39 pm, A.T.Hofkamp [EMAIL PROTECTED] wrote: On 2008-01-23, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi, I am looking for a HTML parser who can parse a given page into a DOM tree, and can reconstruct the exact original html sources. Why not keep a copy of the original data instead? That would be VERY MUCH SIMPLER than trying to reconstruct a parsed tree back to original source text. Thank u for your reply. but what I really need is the mapping between each DOM nodes and the corresponding original source segment. Why do you think there is a simple one-to-one relation between nodes in some abstract DOM tree, and pieces of source?, For example, the outermost tag HTML.../HTML is not an explicit point in the tree. If if it is, what piece of source should be attached to it? Everything? Just the text before and after it? If so, what about the source text of the second tag? Last but not least, what do you intend to do with the source-text before the HTML and after the /HTML tags? In other words, you are going to have a huge problem deciding what corresponding original source segment means for each tag. This is exactly the reason why current tools do not do what you want. If you really want this, you probably have to do it yourself mostly from scratch (ie starting with a parsing framework and writing a custom parser yourself). That usually boils down to attaching source text to tokens in the lexical parsing phase. If you have a good understanding of the meaning of corresponding original source segment, AND you have perfect HTML, this is doable, but not very nice. There exist parsers that can do what you want IF YOU HAVE PERFECT HTML, but using those tools implies a very steep learning curve of about 2-3 months under the assumption that you know functional languages (if you don't, add 2-3 months or so steep learning curve :) ). If you don't have perfect HTML, you are probably more or less lost. Most tools cannot deal with that situation, and those that can do smart re-shuffling to make things parsable, which means there is really no one-to-one mapping any more (after re-shuffling). In other words, I think you really don't want what you want, at least not in the way that you consider now. Please give us information about your goal, so we can think about alternative approaches to solve your problem. sincerely, Albert -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a HTML parser who can reconstruct the original html EXACTLY?
[EMAIL PROTECTED] wrote: Hi, I am looking for a HTML parser who can parse a given page into a DOM tree, and can reconstruct the exact original html sources. Strictly speaking, I should be allowed to retrieve the original sources at each internal nodes of the DOM tree. I have tried Beautiful Soup who is really nice when dealing with those god damned ill-formed documents, but it's a pity for me to find that this guy cannot retrieve original sources due to its great tidy job. Since Beautiful Soup, like most of the other HTML parsers in python, is a subclass of sgmllib.SGMLParser to some extent, I have investigated the source code of sgmllib.SGMLParser, see if there is anything I can do to tell Beautiful Soup where he can find every tag segment from HTML source, but this will be a time-consuming job. so... any ideas? A while ago I had a similar need, but my solution may not solve your problem. I wanted to rewrite URLs contained in links and images etc, but not modify any of the rest of the HTML. I created an HTML parser (based on sgmllib) with callbacks as it encounters tags and attributes etc. It is easy to process a stream without 'damaging' the beautiful orginal structure of crap HTML - but it doesn't provide a DOM. http://www.voidspace.org.uk/python/recipebook.shtml#scraper All the best, Michael Foord http://www.manning.com/foord cheers kai liu -- http://mail.python.org/mailman/listinfo/python-list
Is there a HTML parser who can reconstruct the original html EXACTLY?
Hi, I am looking for a HTML parser who can parse a given page into a DOM tree, and can reconstruct the exact original html sources. Strictly speaking, I should be allowed to retrieve the original sources at each internal nodes of the DOM tree. I have tried Beautiful Soup who is really nice when dealing with those god damned ill-formed documents, but it's a pity for me to find that this guy cannot retrieve original sources due to its great tidy job. Since Beautiful Soup, like most of the other HTML parsers in python, is a subclass of sgmllib.SGMLParser to some extent, I have investigated the source code of sgmllib.SGMLParser, see if there is anything I can do to tell Beautiful Soup where he can find every tag segment from HTML source, but this will be a time-consuming job. so... any ideas? cheers kai liu -- http://mail.python.org/mailman/listinfo/python-list
