plt = ggplot(data, aes(x='date', y='value', color='variable', group='variable')
    ) + scale_x_date(labels=date_format('%y-%m-%d'), limits=(data.date.min(
    ) - dt.timedelta(2), data.date.max() + dt.timedelta(2))) + geom_line(
    ) + facet_grid('variable', scales='free_y')
plt.show()
ggplot multiple plots in one object