How do I run a while loop in tkinter window while it is open?

The mainloop() is the main reason for the window to be displayed continuously. When the while loop is running, the mainloop() does not get executed until the while loop ends. And because in your case the while loop never ends, the code including the mainloop() keeps waiting for its turn to be executed.

To overcome this issue you will have to put all the widgets you want to be displayed in the window along with the mainloop() inside the while loop

Like this:

import tkinter as tk

root = tk.Tk()

i = 0

while i == 0:

    def choice1():
        list1[a1].implement()
        list1.remove(list1[a1])

    def choice2():
        list2[a2].implement()
        list2.remove(list2[a2])


    button1 = tk.Button(root, text=list1.headline, command=choice1)
    button2 = tk.Button(root, text=list2.headline, command=choice2)

    root.mainloop()

You should probably put root.mainloop in the loop, otherwise it will never execute. If mainloop() doesn't execute, the window won't stay open.

And also: you need to call the functions, defining them isn't enough. So instead of in the loop only having the def choice1() and def choice2() you need to also have choice1() and choice2() in the loop, otherwise it won't execute those commands.

And one more thing: you need to pack() the buttons, so add the lines button1.pack() and button2.pack(). The buttons also need to be before the loop, which means your def choice1() and def choice2() need to be before the loop also. (The buttons will never show up otherwise)

tkinter runs in its own loop, each button/widget/element can be tied to more advanced functions. Judging by your script, you have your functions built into your loop, if you place them outside of the loop, you can then enhance their usability.

Your code:

root = Tk()
i=0
while i==0:
    def choice1():
        list1[a1].implement()
        list1.remove(list1[a1])
    def choice2():
        list2[a2].implement()
        list2.remove(list2[a2])

button1 = tk.Button(root, text=list1.headline, command=choice1)
button2 = tk.Button(root, text=list2.headline, command =choice2)
root.mainloop()

Suggested code:

root = Tk()

i=0

def choice1():
    list1[a1].implement()
    list1.remove(list1[a1])

def choice2():
    list2[a2].implement()
    list2.remove(list2[a2])

while i==0:

 # put here, what this extra loop will do.#

button1 = tk.Button(root, text=list1.headline, command=choice1)
button2 = tk.Button(root, text=list2.headline, command =choice2)
root.mainloop()

I have a while loop that I want to run while the Tkinter window is open but the Tkinter window doesn't even open when the while loop is running.

You are missing grid(), place(), and pack()

Put the Button widgets and mainloop() inside while/else block.

Snippet:

import tkinter as tk

root = tk.Tk()
i=0
while i==0:
    def choice1():
        list1[a1].implement()
        list1.remove(list1[a1])
    def choice2():
        list2[a2].implement()
        list2.remove(list2[a2])

    button1 = tk.Button(root, text='list1.headline', command=choice1).pack()
    button2 = tk.Button(root, text='list2.headline', command =choice2).pack()
    root.mainloop()

Screenshot: