Using PyPlot under emacs iESS

I’m trying PyPlot under emacs iESS mode. I start with:
import PyPlot; const plt = PyPlot
plt.figure does nothing. I need to do
plt.pygui(true)``, then figures will appear. Without plt.pygui(true)no figures appear, even withshow()```

I don’t want to always have to remember to type plt.pygui(true), what do you recommend?