Label keeps on appearing - python-3.x

Question

SO I am using Python 3.4 and tkinter.
And when I call a function again n again which contains a label, the label keeps on appearing in window but previous label doesn't go away?
How can I remove any printed label from GUI window as soon as function is called and then display new one?
Here is the code:-
#def prestart():
#here I check if number of match is okay, if not, user is redirected to setting else, I call start()
def start():
#CPU Choice
cpu_choice = Label(historyframe, text = "CPU Choosed: {}".format(dict['cpu_choice']))
#Played Match
#played_num_of_match = Label(scoreframe, text = "Number of Matches Played: {}".format(int(dict['match_played'])))
#Display Status
status_disp = Label(scoreframe, text = "Current Status: {}".format(dict['status']))
if(int(dict['match_played']) < int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
elif(int(dict['match_played']) == int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
cp = dict['cpu_point']
up = dict['user_point']
result(cp, up)
cpu_choice.pack(fill = X)
scoreframe.grid(row = 2, column = 0)
This function just updates the display!
def send_value(x):
#Here I run logic of game and change value of key in dictionary and call start() at end of change.
Now, the choice buttons are not in any definition as they don't need to be called again n again. I just make playframe disappear n appear!
Here is the code for them:-
#Display Question
question = Label(playframe, text = "Rock? Paper? Scissor?")
#Rock
rock = Button(playframe, text = "Rock!", command = lambda: send_value("ROCK"))
#Paper
paper = Button(playframe, text = "Paper!", command = lambda: send_value("PAPER"))
#Scissor
scissor = Button(playframe, text = "Scissor!", command = lambda: send_value("SCISSOR"))
So when user clicks Rock/Paper/Scissor, I just change key value in dictionary! But if I keep the label outside function, it doesn't get auto updated!
Everything else is working perfectly. I'll kind of now start to make code cleaner.

Answer 1

Try something like this instead of creating a new label every time:
import Tkinter as tk
class Window():
def __init__(self, root):
self.frame = tk.Frame(root)
self.frame.pack()
self.i = 0
self.labelVar = tk.StringVar()
self.labelVar.set("This is the first text: %d" %self.i)
self.label = tk.Label(self.frame, text = self.labelVar.get(), textvariable = self.labelVar)
self.label.pack(side = tk.LEFT)
self.button = tk.Button(self.frame, text = "Update", command = self.updateLabel)
self.button.pack(side = tk.RIGHT)
def updateLabel(self):
self.i += 1
self.labelVar.set("This is new text: %d" %self.i)
root = tk.Tk()
window = Window(root)
root.mainloop()
Important points:
1) A class is used, as it is much easier to pass values around when all Tkinter objects and variables are member variables, accessible from all of your GUI functions.
2) updateLabel does not create a new Label. It simply updates the StringVar() object to hold new text every time you call the function. This is accomplished with the textvariable = self.labelVar keyword when creating my Label widget.
PS: This is done in Python 2.5 so for this code to work for you, change Tkinter to tkinter
EDIT 06/19/2015:
If you want to implement something similar to what I have with your code, without using a class, you'll need to pass around references to your variables.
1) Change start:
Your Labels cpu_choice, status_disp, etc. should be created outside of the function; likely in the same location as question, rock, paper, scissors, etc. You will also pack them outside of the function as well. Same with all the calls to .grid inside of start; you shouldn't need to call pack or grid more than once: right when you create the widget.
The following lines:
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
Can be done outside of the function as well; you execute these 3 statements under both the if and the elif conditions. This means they aren't really conditional statements; they are done regardless of the validity of the condition.
2) Create a StringVar for both cpu_choice & status_disp & edit the Labels as follows (remember, outside of the function):
cpu_choice_text = StringVar()
cpu_choice_text.set("Set this to whatever is shown at the start of the game")
cpu_choice = Label(historyframe, text = cpu_choice_text.get(), textvariable = cpu_choice_text)
cpu_choice.pack(fill = X)
# And do this same thing for status_disp
3) When you call start, you will now pass it cpu_choice_text & status_disp_text (or whatever they are called). Instead of trying to change the text field of the Label frame, you may now use a set call on the StringVar which is connected to the Label & the Label will automatically update. Example:
def start(cpu_choice_text, status_disp_text):
cpu_choice.set(text = "CPU Choice: {}".format(dict['cpu_choice']))
...
Alternatively, wrap it all in a class and make it much easier for yourself by using self on every Tkinter variable & widget. In this way you won't need to pass variables to your functions, just access member variables directly as I have with self.i, self.labelVar in my example.

Answer 2

Each time you call start you create new labels and use grid to place them in the same spot as the old labels. The best solution is to only create the labels once, but if you insist on creating new labels each time start is called, you need to delete the old labels first.
You can use the destroy() method of a label to destroy it, though for that to work you must keep a global reference of the label.