Showing the plot window more than once

Question

import matplotlib
import pylab
x=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
y=[2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
plotting=pylab.plot(x,y)
pylab.show(plotting)

The code above (specifically the last line) would pop up the graph below:

If I close the graph window, and run the last line (>>>pylab.show(plotting)) again, the graph would not pop up again. Why is that so? The code above was run in Python 2.7.3.

Answer 1

Because when you close the window python tears down and deletes the figure. Calling show again does nothing because there is no figure to show.

Passing an arguement to show like you do here does nothing (doc). The only argument that show takes is a key-word argument of block.