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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 get_column_names(self, X):
 """Return iterable containing columns for the given array X. Args: X: `numpy.ndarray` or `pandas.DataFrame`. Returns: iterable: columns for the given matrix. """

        if isinstance(X, pd.DataFrame):
            return X.columns

        return range(X.shape[1])