问unicode python 3等效

EN

class NavigableString(unicode_literals, PageElement):

    def toEncoding(self, s, encoding=None):
    """Encodes an object to a string in some encoding, or to Unicode.
    ."""
    if isinstance(s, unichr()):
        if encoding:
            s = s.encode(encoding)
    elif isinstance(s, str):
        if encoding:
            s = s.encode(encoding)
        else:
            s = unicode_literals(s)
    else:
        if encoding:
            s  = self.toEncoding(str(s), encoding)
        else:
            s = unicode_literals(s)
    return s