Why don't these tkinter programs behave identically?

Question

I have 2 codes I made. The 2nd one is based off of the first one. Unfortunately for some reason the 2nd one doesn't work even though the first one does.

First code:

import time

from Tkinter import *



root = Tk()

t=StringVar()

num=1

t.set(str(num)

thelabel = Label(root, textvariable=t).pack()



def printnum (x):

    while x<= 100:

        t.set(str(x))

        x += 1

        root.update()

        time.sleep(30)



printnum(num)

root.mainloop()

This code works like a charm. Here is the other one.

Second code:

#!/usr/bin/python

# -*- coding: latin-1 -*-



import Adafruit_DHT as dht

import time

from Tkinter import *



root = Tk()

k=StringVar()

num = 1

k.set(str(num))

thelabel = Label(root, textvariable=k).pack

def printnum(x):

    while x <= 10000000000000:

       h,t = dht.read_retry(dht.DHT22, 4)

       newtext = "Temp%s*C Humidity=%s" %(t,h)

       k.set(newtext)

       x += 1

       root.update

       time.sleep(30)



printnum(num)

root.mainloop()

The code runs but it doesn't do anything, no window pops up like the other code does. Please help I cannot figure out how to fix this. Or why the first one works and the second one doesn't.

Answer 1

root.update doesn't do anything. You need to add ():

root.update()

That being said, your algorithm is the wrong way to run periodic tasks in tkinter. See http://stackoverflow.com/a/37681471/7432

Why don't these tkinter programs behave identically?

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