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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 _maybe_dt_array(array):
 """ Extract numpy array from single column data table """

    if not isinstance(array, DataTable) or array is None:
        return array

    if array.shape[1] > 1:
        raise ValueError('DataTable for label or weight cannot have multiple columns')

    # below requires new dt version
    # extract first column
    array = array.to_numpy()[:, 0].astype('float')

    return array