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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 IsFile(v):
 """Verify the file exists. True """

    try:
        if v:
            v = str(v)
            return os.path.isfile(v)
        else:
            raise FileInvalid('Not a file')
    except TypeError:
        raise FileInvalid('Not a file')