Use a column as X and another column as Y
df = pd.DataFrame({'Support':[1, 2, 3, 4, 5], 'Mean':[10, 30, 20, 10, 40]})
df.plot(x = 'Support', y='Mean')
Use index as X, and a column as Y
df = pd.DataFrame({'Support':[1, 2, 3, 4, 5], 'Mean':[10, 30, 20, 10, 40]})
df = df.set_index('Support')
df.plot(y='Mean', use_index = True)