Legend not showing up in Matplotlib stacked area plot

Question

I am creating a stacked line/area plot using plt.fill_between() method of the pyplot, and after trying so many things I am still not able to figure why it is not displaying

Answer 1

Only to give an update about this matter as I as looking for it. At 2016, PolyCollection already provide support to the label attribute as you can see:

https://github.com/matplotlib/matplotlib/pull/3303#event-182205203