'Generate Description HTML for each book.
Loop though books, write Description HTML for each book.
Inputs:
books_by_title (list)
Output:
(files): Description HTML for each book'

def generate_html_descriptions(self):

    self.update_progress_full_step(_('Descriptions    HTML'))
    for (title_num, title) in enumerate(self.books_by_title):
        self.update_progress_micro_step(('%s    %d    of    %d' % (_('Description    HTML'), title_num, len(self.books_by_title))), (float(((title_num * 100) / len(self.books_by_title))) / 100))
        soup = self.generate_html_description_header(title)
        outfile = open(('%s/book_%d.html' % (self.content_dir, int(title['id']))), 'w')
        outfile.write(soup.prettify())
        outfile.close()
