Pyplot will only pop up a figure window if
matplotlib.rcParams['interactive'] == True
This is the case if you:
- have previous called
plt.ion()
in your script, or - equivalently, called
matplotlib.interactive(True)
, or - started an ipython session with the
--pylab
option at the command line.
When interactive mode is off, you generally have to call plt.show()
explicitly to make the figure window pop up. This is because we often want to call plot multiple times to draw various things before displaying the figure (which is a blocking call).
Edit (after the question was modified):
One reason for plt.show()
not popping up a figure window is that you haven't activated an interactive backend. Check the output of plt.get_backend()
- if it returns 'agg'
, for example, you have a non-interactive backend.
If this is your problem, you may add lines like
import matplotlib
matplotlib.use('MacOSX')
At the start of your script to specify the backend. This needs to be placed before any other matplotlib related imports.
To make such a change permanent, you can specify a different backend as default by modifying your matplotlib rcfile. The location of this file is found by calling matplotlib.matplotlib_fname()
.