Given an argument string this attempts to split it into small parts.

def split_arg_string(string):
    """Given an argument string this attempts to split it into small parts."""
    rv = []
    for match in re.finditer(r"('([^'\\]*(?:\\.[^'\\]*)*)'"
                             r'|"([^"\\]*(?:\\.[^"\\]*)*)"'
                             r'|\S+)\s*', string, re.S):
        arg = match.group().strip()
        if arg[:1] == arg[-1:] and arg[:1] in '"\'':
            arg = arg[1:-1].encode('ascii', 'backslashreplace') \
                .decode('unicode-escape')
        try:
            arg = type(string)(arg)
        except UnicodeError:
            pass
        rv.append(arg)
    return rv