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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 natural_sort(item):
 """ Sort strings that contain numbers correctly. "['v1.2.1', 'v1.2.3', 'v1.2.5', 'v1.2.15', 'v1.3.3', 'v1.3.12']" """

    if item is None:
        return 0

    def try_int(s):
        try:
            return int(s)
        except ValueError:
            return s
    return tuple(map(try_int, re.findall(r'(\d+|\D+)', item)))