I am using matplotlib to draw charts and graphs.
When I plot the chart using the command
a = (1,2,3,4)
pylab.show() # blocks here
In IPython started with
-pylab it should not block.
ion() you turn the interactive mode on.
show() does not block your system
plot(x, y) updated your plot.
ioff() turns interactive mode off. Useful if you add lots of data and don't
want to update every little detail.