Thanks very much to all those who responded to me and thanks to my good
buddy and Python wiz, Kirke. I've included my code below, which
periodically checks if a file is changed, and if so, it changes the
image displayed in a window. The trick (as suggested) was to use "after"
to get the event to repeatedly call itself. In the code below this is
showStatus.after() at the end of the checkFileMod() function.
--
import Tkinter
import os
root = Tkinter.Tk()
# initialize parameters
checkFile = "C:/BTL/Code/GC/IPSi/test3.txt" # check if this file
changed
img1=Tkinter.PhotoImage(file='./img1.gif') # display image 1
img2=Tkinter.PhotoImage(file='./img2.gif') # display image 2
interval = 3000 # time [msec] between
checking
# label widget shows status of image being displayed
showStatus = Tkinter.Label()
showStatus.pack()
# canvas widget displays image that changes when file changes
canvas=Tkinter.Canvas(root, width=400, height=400)
canvas.create_image(145,280, image=img1)
canvas.bind("<Button-1>", quitThis) # bind left mouse button to quit
app
canvas.pack()
# function quits application
def quitThis(event):
canvas.destroy()
root.destroy()
root.quit()
# function changes canvas if file is modified
def checkFileMod():
global imgNum
global fileStatus, fileStatusB4
fileStatus = os.stat(checkFile)
print "file status: ", fileStatus.st_mtime
if fileStatus != fileStatusB4:
print "CHANGED"
if imgNum == 1:
showStatus.config(text="img2")
imgNum = 2
canvas.create_image(145,280, image=img2)
canvas.pack()
else:
showStatus.config(text="img1")
imgNum = 1
canvas.create_image(145,280, image=img1)
canvas.pack()
fileStatusB4 = fileStatus
showStatus.after(interval, checkFileMod)
# run with initial values before loop
imgNum = 1
showStatus.config(text="img1")
fileStatusB4 = os.stat(checkFile) # file status before
#loop
checkFileMod()
showStatus.mainloop()
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