If you want to save your plot and edit it later, you should try the hints given in this
thread
If your plot is still active in a [I]python shell, you can edit all properties and make a redraw. The following example is for moving the legend from default location to right upper corner after examination.
In [51]: import numpy as np
In [52]: import pylab as pl
In [53]: v = np.arange(10)
In [54]: pl.figure(1)
Out[54]: <matplotlib.figure.Figure at 0x253a250>
In [55]: # if needed, use pl.figure(1) again to make it active
In [56]: pl.plot(v)
Out[56]: [<matplotlib.lines.Line2D at 0x456a450>]
In [60]: pl.legend('v')
Out[60]: <matplotlib.legend.Legend at 0x4591150>
In [61]: pl.show(block=False)
In [62]: # keyword block=False to issue further commands
In [63]: pl.legend('v',loc=2)
Out[63]: <matplotlib.legend.Legend at 0x45962d0>
In [64]: pl.show(block=False)
In [67]: # now the legend is in the upper right corner