Pandas sandwich: show first and last n lines of dataframe

sandwich.py

def sandwich(df, rows=3):
    '''
    Display n rows of head and tail of dataframe.

    Input:
        df - dataframe of interest
        rows - integer number of rows from each end of dataframe to display

    Output:
        dataframe
    '''

    fill_row = pd.DataFrame(np.array(['...']*df.shape[1]).reshape(1, -1),
                            columns=df.columns,
                            index=['...'])

    return pd.concat([df.head(rows), fill_row, df.tail(rows)])