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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def none_to_blank(s, exchange=''):
 """Replaces NoneType with '' '' '' u'something' [u'1', ''] :param s: String to replace :para exchange: Character to return for None, default is blank ('') :return: If s is None, returns exchange """

    if isinstance(s, list):
        return [none_to_blank(z) for y, z in enumerate(s)]
    return exchange if s is None else unicode(s)