Untitled

##the problem
I don't understand why my doc tests are failing. The self.whitelist variable seems like it's being treated as a static variable instead of a class one.

##the errors:
**********************************************************************
File "my_sanitizer.py", line 87, in __main__.HTMLFilterFactory.add_tags
Failed example:
    z.white_list ==         {'p': {}, 'i': {}, 'em': {}, 'strong': {}, 'b': {}, 'u': {}, 'h1': {}}
Expected:
    True
Got:
    False
**********************************************************************
File "my_sanitizer.py", line 97, in __main__.HTMLFilterFactory.remove_tags
Failed example:
    y.white_list ==         {'p': {}, 'i': {}, 'em': {}, 'strong': {}, 'b': {}, 'u': {}, 'h1': {}}
Expected:
    True
Got:
    False
**********************************************************************
File "my_sanitizer.py", line 100, in __main__.HTMLFilterFactory.remove_tags
Failed example:
    y.white_list
Expected:
    {}
Got:
    {'body': {'id': (<function <lambda> at 0x896b924>,)}}
**********************************************************************
2 items had failures:
   1 of   3 in __main__.HTMLFilterFactory.add_tags
   2 of   5 in __main__.HTMLFilterFactory.remove_tags
***Test Failed*** 3 failures.

##my code
import BeautifulSoup

class HTMLFilterFactory:
    """
    This class allows you to dynamically create a custom HTML filter. You create
    a factory and add tags to it using bracket syntax. The value
    you specify is another dictionary that contains valid attribute names as
    keys and filter literals as values.

    The exception is inner_html which is treated as inner_html instead of
    an attribute.

    If you set an attribute's value to an empty string, the attribute will be
    deleted.

    >>> x = HTMLFilterFactory()
    >>> soria_only = lambda text: text == "soria" and "soria" or ""
    >>> x.add_tags("body p")
    >>> x["body"]["id"] = (soria_only,)
    >>> x["p"]["id"] = (soria_only,)
    >>> x["p"]["inner_html"] = (soria_only,)
    >>> x(r'''<BODY ID = "soria" ONLOAD = "alert('XSS')"><p id= 'tundra'>inner html that isn't soria</p></BODY>''')
    u'<body id="soria"><p></p></body>'
    """
    def __init__(self, white_list = {}, tags = ""):
        """You may optionally add a string of tags as per the add_tags method"""
        self.white_list = white_list
        self.add_tags(tags)

    def __getitem__(self, key):
        '''This returns the whitelisted tag by that name'''
        return self.white_list[key]

    def __setitem__(self, key, value):
        '''This assigns the whitelisted key to the value. The value should be
        an empty dictionary or a dictionary with valid attribute names as keys
        that point to sequences of filters you wish to apply to the attribute
        value.
        >>> x = HTMLFilterFactory()
        >>> soria_only = lambda text: text == "soria" and "soria" or ""
        >>> x["body"] = {"id":(soria_only,)}'''
        self.white_list[key] = value

    def __call__(self, text):
        '''This applies the filters to the text and returns the text'''
        soup = BeautifulSoup.BeautifulSoup(text)

        for tag in soup.findAll(True):
            if tag.name not in self.white_list:
                tag.hidden = True
            else:
                for attr, val in tag.attrs:
                    if attr in self.white_list[tag.name]:
                        for filter in self.white_list[tag.name][attr]:
                            tag[attr] = filter(val)
                        if tag[attr] == '':
                            del(tag[attr])
                    else:
                        del(tag[attr])
                if self.white_list[tag.name].has_key("inner_html") == True:
                    #If this tag has filters for inner_html, use the filters
                    #on the inner_html of the tag
                    for filter in self.white_list[tag.name]["inner_html"]:
                        inner_html = tag.firstText(
                            text = True, recursive = False)
                        tag.firstText(
                            text = True, recursive = False).replaceWith(
                                filter(inner_html))

        return unicode(soup)

    def add_tags(self, tags):
        '''This whitelists one or more tags without specifying attributes or
        filters. (It's good if you want to add a lot of empty tags)
        >>> z = HTMLFilterFactory()
        >>> z.add_tags("p i em strong b u h1")
        >>> z.white_list == \
        {'p': {}, 'i': {}, 'em': {}, 'strong': {}, 'b': {}, 'u': {}, 'h1': {}}
        True'''
        for tag in tags.split():
            self.white_list[tag] = {}

    def remove_tags(self, tags):
        '''This removes one or more tags from the whitelist.
        >>> y = HTMLFilterFactory()
        >>> y.add_tags("p i em strong b u h1")
        >>> y.white_list == \
        {'p': {}, 'i': {}, 'em': {}, 'strong': {}, 'b': {}, 'u': {}, 'h1': {}}
        True
        >>> y.remove_tags("p i em strong b u h1")
        >>> y.white_list
        {}'''
        for tag in tags.split():
            del(self.white_list[tag])

if __name__ == "__main__":
    import doctest
    doctest.testmod()