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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 _calc_T_var(self,X) -> int: """Calculate the number of samples, T, from the shape of X"""

        shape = X.shape
        tensor_rank: int = len(shape)
        if tensor_rank == 0:
            return 1
        if tensor_rank == 1:
            return shape[0]
        if tensor_rank == 2:
            if shape[1] > 1:
                raise ValueError('Initial value of a variable must have dimension T*1.')
            return shape[0]