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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 is_prettytable(string):
 """ returns true if the input looks like a prettytable """

    return type(string).__name__ in {'str','unicode'} and (
        len(string.splitlines()) > 1
    ) and (
        all(string[i] == string[-i-1] for i in range(3))
    )