determine if image is in top half of article

models.py

def selected_image(self, lang='en', user_langs=None):
    """
    For display at the top of an article, show the largest selected image, as long as it's not near the top of the article body
    """

    # attachments
    if self.image_attachments():
        # sort by size descending
        attachments = sorted(self.image_attachments(), key=lambda x: x.file.size, reverse=True)

        # check all attachments for selected attribute, and return the first (biggest) one
        for a in attachments:
            if a.selected:
                filename = os.path.basename(a.file.name) # just the filename
                filename = quoteattr(filename)[1:-1] # remove automatic encapsulating quotes
                filename = escape(filename) # HTML encode
                filename = filename.strip() # trim whitespace

                body = self.body

                #a.description = a.description(lang, user_langs)
                #a.description = re.sub('<p[^>]*>(.+?)</p\s*>','\\1', a.description)

                #character count deemed acceptable for showing featured image, to reduce chances of showing the same image twice in proximity at the top of the article
                threshold = 1750

                """
                this is what is in the body!!!

                New Year&#39;s food table Loomis_sm.jpg

                BUT, it has an escaped ampersand, so THIS is what's in there?!?

                New Year&amp;#39;s food table Loomis_sm.jpg

                """

                # debug, returns true if greater than threshold
                # return body.find(filename) >= threshold

                # if selected image is in the second half of article or not in the article, show it
                if body.find(filename) >= threshold or body.find(filename) == -1:
                    return a