index        value
0            3.075
1           44.338
2           10.030

def get_amplitude(extremas, col, n):

    amps = abs(extremas[col].diff(periods=1))
    amps.sort_values(inplace=True, ascending=False)
    amps = amps.head(n)

    df = pd.DataFrame({'local minima': extremas.loc[amps.index, 'value'],
                       'local maxima': extremas.loc[amps.index - 1, 'value']})

    return df

local maxima  local minima
17398        433.75           NaN
17399           NaN        -99.00
17551        438.00           NaN
17552           NaN        -88.25
21262        437.75           NaN
21263           NaN       -120.75

local maxima  local minima
0        433.75           -99.00
1        438.00           -88.25
3        437.75           -120.75