Return whether plots are updated after every plotting command.
The interactive mode is mainly useful if you build plots from the command line and want to see the effect of each command while you are building the figure.
In interactive mode:
newly created figures will be shown immediately;
figures will automatically redraw on change;
pyplot.showwill not block by default.
In non-interactive mode:
newly created figures and changes to figures will not be reflected until explicitly asked to be;
pyplot.showwill block by default.