No plot window in matplotlib
You can type
import pylabpylab.show()or better, use ipython -pylab.
Since the use of pylab is not recommended anymore, the solution would nowadays be
import matplotlib.pyplot as pltplt.plot([1,2,3])plt.show()
pylab.show() works but blocks (you need to close the window).
A much more convenient solution is to do pylab.ion() (interactive mode on) when you start: all (the pylab equivalents of) pyplot.* commands display their plot immediately. More information on the interactive mode can be found on the official web site.
I also second using the even more convenient ipython -pylab (--pylab, in newer versions), which allows you to skip the from … import … part (%pylab works, too, in newer IPython versions).