if __name__ == '__main__':
    df = pd.DataFrame({'date': ['2016-08-01', '2016-08-08', '2016-08-15',
        '2016-08-22'], 'x': [100, 50, 24, 0], 'a': [20, 0, 18, 10]})
df['date'] = pd.to_datetime(df['date'])
ggplot multiple plots in one object