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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 romanise(number):
 """Return the roman numeral for a number. Note that this only works for number in interval range [0, 12] since at the moment we only use it on realtime earthquake to conver MMI value. :param number: The number that will be romanised :type number: float :return Roman numeral equivalent of the value :rtype: str """

    if number is None:
        return ''

    roman_list = ['0', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII',
                  'IX', 'X', 'XI', 'XII']
    try:
        roman = roman_list[int(number)]
    except ValueError:
        return None
    return roman