import re

def unescape(text):
    fd = re.findall(r'\&\#\d+\;', text)
    if len(fd) == 0:
        return text
    for n in set(fd):
        fk = re.search(r'\d+', n).group()
        text = text.replace(n, chr(int(fk)))
    return unescape(text)
print(unescape("hello world ä"))