How to always center labels on top of one another

Question

In my code, there are checkboxes to allow the data printed to be selected. But if I use .place and uncheck certain boxes, there will be a gap between the displays. E.g:

But, if i use pack(), the code will be stuck on top of the window. E.g:

What should i do to make them always on top of each other, while also being centered.

Answer 1

from tkinter import *

#functions

def get_distance_travelled():
    # your code to find the distance travelled. I have given a dummy value
    return 15 #Remove this line and change according to yours
    
def get_max_height():
    #your code to find max_height. I have given a dummy value
    return 100 #Remove this line and change according to yours

def get_final_velocity():
    # your code to get final velocity. I have given a dummy value
    return 1000 #Remove this line and change according to yours
    
def get_flight_time():
    # your code to get flight_time.I have given a dummy value
    return '10:10' #Remove this line and change according to yours
    
def show_items():
    pop = Toplevel(root)
    pop.geometry('300x200')
    fn_lst = [get_distance_travelled(), get_max_height(), get_final_velocity(), get_flight_time() ]
    for i in range(len(ls)):
        if vardct[i].get()==1:
            
            # Remove the word 'Display ' from Display texts
            txt = keydct[i].replace('Display ', '')
            Label(pop, text=f'{txt} : {fn_lst[i]}').pack()

#design

root = Tk()
root.geometry('300x200')


# list containing display texts
ls =    ['Display Distance Travelled', 
         'Display Max Height',
        'Display Final Velocity',
        'Display Flight Name']
        
        
# Create 3 dicts say for display texts, intvars, and wdgts
keydct, vardct, wdgdct = {}, {}, {}

#create widgets and pack
for i in range(len(ls)):
    keydct[i] = ls[i]
    vardct[i] = IntVar()
    wdgdct[i] = Checkbutton(root, text = keydct[i], variable = vardct[i])
    wdgdct[i].pack() 


    
     
    
btn = Button(root, text = 'Show', command=show_items)
btn.pack()
root.mainloop()