No plot window in matplotlib

You can type

import pylab
pylab.show()

or better, use ipython -pylab.


Since the use of pylab is not recommended anymore, the solution would nowadays be

import matplotlib.pyplot as plt

plt.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).