trick

unicode.py

import unicodedata


def must_be_ascii(raw):
    '''Convert all non-ascii characters to ascii substitutes.

    :param raw: raw input.
    '''
    if not isinstance(raw, (str, unicode)):
        raise TypeError('Cannot convert to ascii, expected str or unicode.')
    if not isinstance(raw, unicode):
        raw = raw.decode('u8')

    return unicodedata.normalize('NFKD', raw) \
        .encode('ascii', 'ignore') \
        .decode('u8')