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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 _realpath(path):
 """Return the real path of `path` Is equivalent to ``realpath(abspath(expanduser(path)))``. Of the particular notice is the hack dealing with the unfortunate sitaution of running native-Windows python (os.name == 'nt') inside of Cygwin (abspath starts with '/'), which apparently normal os.path.realpath completely messes up. """

    # there is a bug in cygwin for os.path.abspath() for abs paths
    if sys.platform == 'cygwin':
        if path[1:3] == ':\\':
            return path
        elif path[1:3] == ':/':
            path = "/cygdrive/" + path[0] + path[2:]
        return os.path.abspath(os.path.expanduser(path))
    return os.path.realpath(os.path.abspath(os.path.expanduser(path)))