+
+def add_table_of_themes(root):
+ try:
+ from sortify import sortify
+ except ImportError:
+ sortify = lambda x: x
+
+ book_themes = {}
+ for fragment in root.findall('.//a[@class="theme-begin"]'):
+ if not fragment.text:
+ continue
+ theme_names = [s.strip() for s in fragment.text.split(',')]
+ for theme_name in theme_names:
+ book_themes.setdefault(theme_name, []).append(fragment.get('name'))
+ book_themes = book_themes.items()
+ book_themes.sort(key=lambda s: sortify(s[0]))
+ themes_div = etree.Element('div', id="themes")
+ themes_ol = etree.SubElement(themes_div, 'ol')
+ for theme_name, fragments in book_themes:
+ themes_li = etree.SubElement(themes_ol, 'li')
+ themes_li.text = "%s: " % theme_name
+ for i, fragment in enumerate(fragments):
+ item = etree.SubElement(themes_li, 'a', href="#%s" % fragment)
+ item.text = str(i + 1)
+ item.tail = ' '
+ root.insert(0, themes_div)
+
+