The htmlentitydefs Module

The htmlentitydefs module contains a dictionary with many ISO Latin-1 character entities used by HTML. Its use is demonstrated in Example 5-10.

Example 5-10. Using the htmlentitydefs Module

File: htmlentitydefs-example-1.py import htmlentitydefs entities = htmlentitydefs.entitydefs for entity in "amp", "quot", "copy", "yen": print entity, "=", entities[entity] amp = & quot = " copy = 302251 yen = 302245

Example 5-11 shows how to combine regular expressions with this dictionary to translate entities in a string (the opposite of cgi.escape).

Example 5-11. Using the htmlentitydefs Module to Translate Entities

File: htmlentitydefs-example-2.py import htmlentitydefs import re import cgi pattern = re.compile("&(w+?);") def descape_entity(m, defs=htmlentitydefs.entitydefs): # callback: translate one entity to its ISO Latin value try: return defs[m.group(1)] except KeyError: return m.group(0) # use as is def descape(string): return pattern.sub(descape_entity, string) print descape("<spam&eggs>") print descape(cgi.escape(""))

Finally, Example 5-12 shows how to use translate reserved XML characters and ISO Latin-1 characters to an XML string. This is similar to cgi.escape, but it also replaces non-ASCII characters.

Example 5-12. Escaping ISO Latin-1 Entities

File: htmlentitydefs-example-3.py import htmlentitydefs import re, string # this pattern matches substrings of reserved and non-ASCII characters pattern = re.compile(r"[&<>"x80-xff]+") # create character map entity_map = {} for i in range(256): entity_map[chr(i)] = "&%d;" % i for entity, char in htmlentitydefs.entitydefs.items(): if entity_map.has_key(char): entity_map[char] = "&%s;" % entity def escape_entity(m, get=entity_map.get): return string.join(map(get, m.group()), "") def escape(string): return pattern.sub(escape_entity, string) print escape("") print escape("303245 i 303245a 303244 e 303266") <spam&eggs> å i åa ä e ö