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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 pretty_spaces(level):
 """ Return spaces and new line. :type level: int or None :param level: deep level :rtype: unicode :return: string with new line and spaces """


    if level is None:
        return u''
    return (os.linesep if level >= 0 else u'') + (u' ' * (INDENT * level))