origin of error message

[gordon]

hi
i was trying to create an image using user selection of a file in tix
fileselection box ..and i check for exception like below
<start of code snippet>
....
from string import split
from os.path import basename

....
#this is done inside __init__method
self.imgsel=Fil eSelectBox(self .imgSelectFrame )
....

def button1Click(se lf):
starttime=datet ime.now()
self.okButton.c onfigure(state= DISABLED)

#will clear canvas
self.canvorig.d elete(ALL)
self.canvresult .delete(ALL)
self.resultdisp lay.delete(ALL)

#image file selection by tix widget
self.cursel=sel f.imgsel.select ion.cget("value ")
print "self.cursel:", self.cursel
self.imgsel.sel ection.selectio n_clear()
#here i want to check if anything is selected by user
if self.cursel:
ext=split(basen ame(self.cursel ),'.')[1]
print "image extn:",ext
try:

self.selimg=Ima geTk.PhotoImage (file=self.curs el)
except Exception,inst:
print "xceptn::",inst .message
self.showresult (inst.message," red")
else:

self.selimgtag= self.canvorig.c reate_image(70, 100,image=self. selimg)
self.canvorig.u pdate_idletasks ()

.....
# some other tasks done
.....

else:
#no file was selected by user
print "self.cursel=", self.cursel
self.showresult ("nothing selected","red" )

self.okButton.c onfigure(state= NORMAL)
endtime=datetim e.now()
print "total time:", endtime-starttime,"seco nds"

<end of code snippet>
user is supposed to select an image to be displayed.
when i select some file with a non compatible extension (say .zip)
i get the following output

>>>>

self.cursel: F:/docs/python/gui3.zip
image extn: zip
xceptn:: cannot identify image file
total time: 0:00:00.341000 seconds
Exception exceptions.Attr ibuteError: "PhotoImage instance has no
attribute '_Pho
toImage__photo' " in <bound method PhotoImage.__de l__ of
<ImageTk.PhotoI mage inst
ance at 0x00DA4F08>igno red


My belief was that the message
'total time: 0:00:00.341000 seconds '
should have been the last output message .I don't know where the
Exception exceptions.Attr ibuteError: etc comes from. Already i am
catching the exception when creating PhotoImage .The message 'xceptn::
cannot identify image file' comes from there

Can someone help me find how this error msg happens

gordon