The scientific community often runs iterative code, often in the form of simulation. It's often useful to see the results after each iteration. Accordingly, MATLAB^® has a nice feature that allows you to update the figure, drawnow. This repo brings the same feature to Python's matplotlib, with some extras.

Example:

This is shown with imshow, but python-drawnow allows updates of any figure.

Usage:

# complete implementation of script found in test/test.py
from pylab import *
from drawnow import drawnow, figure
# if global namespace, import plt.figure before drawnow.figure

figure(figsize=(7, 7/2))
def draw_fig():
    subplot(1, 2, 1)
    imshow(x)

    subplot(1, 2, 2)
    imshow(x_hat)
    #show()

x = imread('mandrill.png').mean(axis=2)
k_values = around(logspace(0, 2, num=10))
for k in k_values:
    x_hat = approx(x, k)
    drawnow(draw_fig)

If you want to wait for confirmation after update or the option to drop into a debugger, call drawnow(function_to_draw_figure, confirm=True).

If you only want to show the figure once, call drawnow(function_to_draw_figure, show_once=True)

drawnow does not work in IPython's QtConsole at least for me.

The full documentation is included in the doc strings.

Two options:

1. Run pip install drawnow.
2. Download this repository and run python setup.py install.

This does require small changes to your code. All it should really amount to is moving figure(); plot(...); show() inside a function; not much.