Hi everybody,
I have a question about the behavior of "del()" Python built-in.
In the following example, when I use del() on the copy of a line, it does
not delete it, whereas with the original line, it works. Why? I do not
understand, because the id is the same for the copy and the original:
···
#######################
from pylab import *
import Tkinter as Tk
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
ion()
root = Tk.Tk()
f = Figure( figsize = (8,7) )
veryplot = FigureCanvasTkAgg( f
, master = root )
veryplot.get_tk_widget().pack( side = Tk.LEFT
, expand = Tk.YES
, fill = Tk.BOTH )
b = f.add_subplot( 211 )
t = arange(0.01, 5.0, 0.01)
s1 = sin(2*pi*t)
b.plot( t, s1 )
b.plot( t, s1+1 )
print b.lines
raw_input('press a key to delete a line with a copy')
line_copy = b.lines[-1]
print "original id=", id( b.lines[-1] ), "copy id", id( line_copy )
del( line_copy ) # or b.lines.pop()
b.figure.canvas.draw()
print b.lines
raw_input('press a key to delete a line directly')
print "original id=", id( b.lines[-1] )
del( b.lines[-1] ) # or b.lines.pop()
b.figure.canvas.draw()
print b.lines
raw_input('press a key to quit')
#######################
Thanks in advance,
Julien
--
python -c "print ''.join([chr(154 - ord(c)) for c in '*9(9&(18%.9&1+,\'Z
(55l4('])"
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