Add the x-axis value captions to the code of this graph and change its color to purple gdpdiff[['Country or region', 'GDP per capita']].plot(kind='bar')

gdpdiff = gdpdiff.dropna(subset=['GDP per capita'])
gdpdiff = gdpdiff[gdpdiff['GDP per capita'] > 0]
gdpdiff = gdpdiff.sort_values(by='GDP per capita')

gdpdiff['Country or region'].replace({
    'United States': 'USA',
    'United Kingdom': 'UK'
})
gdpdiff.plot(x='Country or region', y='GDP per capita', kind='bar')