updating python3 tkinter label not working - python-3.x

Question

I can manually update label and entry if i clicked the manual button, but if i clicked the auto button... the console show the random number but the widgets are not updating.
from tkinter import *
import random
import time
def manual_settxt():
for t in range(0,3):
rd = random.randrange(1,100)
labelWidgets[t].configure(text=rd)
entryWidgets[t].delete(0,END)
entryWidgets[t].insert(0,rd)
def auto_settxt():
while True:
time.sleep(3)
for t in range(0,3):
rd = random.randrange(1,100)
print(rd)
labelWidgets[t].configure(text=rd)
entryWidgets[t].delete(0,END)
entryWidgets[t].insert(0,rd)
root = Tk()
namesInput = [1,2,3]
entryWidgets = []
labelWidgets = []
for i in range(0, len(namesInput)):
labelWidgets.append(Label(root,text=namesInput[i],justify='center'))
entryWidgets.append(Entry(root,width=5,justify='center'))
labelWidgets[-1].grid(row=i+1,column=0)
entryWidgets[-1].grid(row=i+1,column=1)
b1 = Button(root, text = "Manual", command=manual_settxt)
b1.grid(row=4,column=0)
b2 = Button(root, text = "Auto", command=auto_settxt)
b2.grid(row=4,column=1)
root.mainloop()

Answer 1

You created an infinite loop. Delete while True.
I refactored some code: used Thread for non-blocking functionality.
Try this
from tkinter import *
import random
import time
from threading import Thread
def manual_settxt():
for index in range(3):
rd = random.randrange(1,100)
labelWidgets[index].configure(text=rd)
entryWidgets[index].delete(0,END)
entryWidgets[index].insert(0,rd)
def job():
for index in range(3):
time.sleep(1)
rd = random.randrange(1,100)
print(rd)
labelWidgets[index].configure(text=rd)
entryWidgets[index].delete(0,END)
entryWidgets[index].insert(0,rd)
def auto_settxt():
Thread(target=job).start()
root = Tk()
namesInput = [1,2,3]
entryWidgets = []
labelWidgets = []
for index, name in enumerate(namesInput):
labelWidgets.append(Label(root, text=name, justify='center'))
entryWidgets.append(Entry(root, width=5, justify='center'))
labelWidgets[-1].grid(row=index+1,column=0)
entryWidgets[-1].grid(row=index+1,column=1)
b1 = Button(root, text = "Manual", command=manual_settxt)
b1.grid(row=4,column=0)
b2 = Button(root, text = "Auto", command=auto_settxt)
b2.grid(row=4,column=1)
root.mainloop()

Answer 2

I use "root.after" and the script seems to be working fine.
from tkinter import *
import random
import time
def manual_settxt():
for index in range(3):
rd = random.randrange(1,100)
labelWidgets[index].configure(text=rd)
entryWidgets[index].delete(0,END)
entryWidgets[index].insert(0,rd)
def auto_settxt():
for index in range(3):
rd = random.randrange(1,100)
print(rd)
labelWidgets[index].configure(text=rd)
entryWidgets[index].delete(0,END)
entryWidgets[index].insert(0,rd)
root.after(1000, auto_settxt)
root = Tk()
namesInput = [1,2,3]
entryWidgets = []
labelWidgets = []
for index, name in enumerate(namesInput):
labelWidgets.append(Label(root, text=name, justify='center'))
entryWidgets.append(Entry(root, width=5, justify='center'))
labelWidgets[-1].grid(row=index+1,column=0)
entryWidgets[-1].grid(row=index+1,column=1)
b1 = Button(root, text = "Manual", command=manual_settxt)
b1.grid(row=4,column=0)
b2 = Button(root, text = "Auto", command=auto_settxt)
b2.grid(row=4,column=1)
root.after(1000, auto_settxt)
root.mainloop()