python - Entry widget contents not changing with function call -

i need change content of entry whenever tkinter frame shown. below have far, , doesn't seem work. have tried use data = self.read() , now.insert(0, data) , has not worked either. if value displayed doesn't changed every time class readlabel1 called.

class readlabel1(tk.frame):     def __init__(self, parent, controller):         tk.frame.__init__(self, parent, bg="blue")          label = tk.label(self, text="somedata:", font = "times 12", bg="blue")         label.place(x=10, y=100) #ack(pady=5,padx=30)          self.smstr = tk.stringvar()         now=tk.entry(self, width=22, textvariable=self.read())         now.place(x=120, y=103)      def read(self):         # code data         return data 

you need turn 'change content of entry' 1 parameter callback, turn 'whenever tkinter frame shown' event, , bind app, event, , callback. here minimal example.

import time import tkinter tk  root = tk.tk() = tk.stringvar() lab = tk.label(root, textvariable=now) lab.pack() def display_now(event):     now.set(time.ctime()) root.bind('<visibility>', display_now) root.bind('<focusin>', display_now) 

minimizing window icon , bringing triggers visibility event. covering , merely uncovering different window did not, @ least not windows. clicking on uncovered, or merely inactivated, window triggered focusin. can experiment more system. used tkinter reference