Python convert html to text and mimic formatting

Question

I'm learning BeautifulSoup, and found many "html2text" solutions, but the one i'm looking for should mimic the formatting:

<ul>
<li>One</li>
<li>Two</li>
</ul>

Would become

* One
* Two

and

Some text
<blockquote>
More magnificent text here
</blockquote>
Final text

to

Some text

    More magnificent text here

Final text

I'm reading the docs, but I'm not seeing anything straight forward. Any help? I'm open to using something other than beautifulsoup.

Answer 1

Python's built-in html.parser (HTMLParser in earlier versions) module can be easily extended to create a simple translator that you can tailor to your exact needs. It lets you hook into certain events as the parser eats through the HTML.

Due to its simple nature you cant navigate around the HTML tree like you could with Beautiful Soup (e.g. sibling, child, parent nodes etc) but for a simple case like yours it should be enough.

html.parser homepage

In your case you could use it like this by adding the appropriate formatting whenever a start-tag or end-tag of a specific type is encountered :

from html.parser import HTMLParser
from os import linesep

class MyHTMLParser(HTMLParser):
    def __init__(self):
        HTMLParser.__init__(self, strict=False)
    def feed(self, in_html):
        self.output = ""
        super(MyHTMLParser, self).feed(in_html)
        return self.output
    def handle_data(self, data):
        self.output += data.strip()
    def handle_starttag(self, tag, attrs):
        if tag == 'li':
            self.output += linesep + '* '
        elif tag == 'blockquote' :
            self.output += linesep + linesep + '\t'
    def handle_endtag(self, tag):
        if tag == 'blockquote':
            self.output += linesep + linesep

parser = MyHTMLParser()
content = "<ul><li>One</li><li>Two</li></ul>"
print(linesep + "Example 1:")
print(parser.feed(content))
content = "Some text<blockquote>More magnificent text here</blockquote>Final text"
print(linesep + "Example 2:")
print(parser.feed(content))

Answer 2

Take a look at Aaron Swartz's html2text script (can be installed with pip install html2text). Note that the output is valid Markdown. If for some reason that doesn't fully suit you, some rather trivial tweaks should get you the exact output in your question:

In [1]: import html2text

In [2]: h1 = """<ul>
   ...: <li>One</li>
   ...: <li>Two</li>
   ...: </ul>"""

In [3]: print html2text.html2text(h1)
  * One
  * Two

In [4]: h2 = """<p>Some text
   ...: <blockquote>
   ...: More magnificent text here
   ...: </blockquote>
   ...: Final text</p>"""

In [5]: print html2text.html2text(h2)
Some text

> More magnificent text here

Final text

Answer 3

I have code for a more simple task: Remove HTML tags, and insert newlines at the appropriate places. Maybe this can be a starting point for you.

Python's textwrap module might be helpful for creating indented blocks of text.

http://docs.python.org/2/library/textwrap.html

class HtmlTool(object):
    """
    Algorithms to process HTML.
    """
    #Regular expressions to recognize different parts of HTML. 
    #Internal style sheets or JavaScript 
    script_sheet = re.compile(r"<(script|style).*?>.*?(</\1>)", 
                              re.IGNORECASE | re.DOTALL)
    #HTML comments - can contain ">"
    comment = re.compile(r"<!--(.*?)-->", re.DOTALL) 
    #HTML tags: <any-text>
    tag = re.compile(r"<.*?>", re.DOTALL)
    #Consecutive whitespace characters
    nwhites = re.compile(r"[\s]+")
    #<p>, <div>, <br> tags and associated closing tags
    p_div = re.compile(r"</?(p|div|br).*?>", 
                       re.IGNORECASE | re.DOTALL)
    #Consecutive whitespace, but no newlines
    nspace = re.compile("[^\S\n]+", re.UNICODE)
    #At least two consecutive newlines
    n2ret = re.compile("\n\n+")
    #A return followed by a space
    retspace = re.compile("(\n )")

    #For converting HTML entities to unicode
    html_parser = HTMLParser.HTMLParser()

    @staticmethod
    def to_nice_text(html):
        """Remove all HTML tags, but produce a nicely formatted text."""
        if html is None:
            return u""
        text = unicode(html)
        text = HtmlTool.script_sheet.sub("", text)
        text = HtmlTool.comment.sub("", text)
        text = HtmlTool.nwhites.sub(" ", text)
        text = HtmlTool.p_div.sub("\n", text) #convert <p>, <div>, <br> to "\n"
        text = HtmlTool.tag.sub("", text)     #remove all tags
        text = HtmlTool.html_parser.unescape(text)
        #Get whitespace right
        text = HtmlTool.nspace.sub(" ", text)
        text = HtmlTool.retspace.sub("\n", text)
        text = HtmlTool.n2ret.sub("\n\n", text)
        text = text.strip()
        return text

There might be some superfluous regexes left in the code.