Tkinter: How to make a button center itself?

Question

I'm making a program in Python and I want to go with a layout that is a bunch of buttons in the center. How do I make a button center itself using pack()?

Answer 1

To center horizontally this should be enough

button.pack(side=TOP)

But to center horizontally and vertically you could use nested frames. Check the following script:

import tkinter as tk

#%% Frames
frameA = tk.Frame(background="#c8c8c8")
frameB = tk.Frame(width=200, height = 200, background="#646464")
# Nested Frame. framebb is created within frameB without width or height
framebb = tk.Frame(frameB, background="#646464")
frameC = tk.Frame(width=100, height = 100, background="bisque")

frameA.pack(side='top', fill=None)
frameB.pack(side='top')
# expand is the key parameter to center the framebb within frameB
framebb.pack(expand=True)
frameC.pack(side='bottom')

#frameA.pack_propagate(False)
frameB.pack_propagate(False)
frameC.pack_propagate(False)

#%% Buttons and Labels
tk.Label(frameA, text = "Text within the frame A").pack()

a = tk.Button(framebb, text = "A").pack()
b = tk.Button(framebb, text = "B").pack()
c = tk.Button(framebb, text = "C").pack()
d = tk.Button(frameC, text = "D").pack()
e = tk.Button(frameC, text = "E").pack()

tk.mainloop()

Another approach could be using the .grid() method

button.grid(row=1,col=0)

the values of row=1,col=0 depend of the position of the other widget in your window

or you can use .place(relx=0.5, rely=0.5, anchor=CENTER)

button.place(relx=0.5, rely=0.5, anchor=CENTER)

Notice that the parameter anchor is referencing the a relative position to the object (in this case button). anchor is not referencing to a position in the window. You could think that the button is a ship that has several anchors so you should choose a coordinate and which anchor you want to fix in that coordinate.

Example using .place():

from tkinter import *  # Use this if use python 3.xx
#from Tkinter import *   # Use this if use python 2.xx
a = Button(text="Center Button")
b = Button(text="Top Left Button")
c = Button(text="Bottom Right Button")

# You can use the strings the referencing the relative position on the button
# strings = n, ne, e, se, s, sw, w, nw, c or center
# Or you can use the constants of tkinter
# N, NE, E, SE, S, SW, W, NW, CENTER
a.place(relx=0.5, rely=0.5, anchor=CENTER)
b.place(relx=0.0, rely=0.0, anchor=NW)
c.place(relx=1.0, rely=1.0, anchor=SE)
mainloop()

Answer 2

this is slightly old now, you have to do this:

import tkinter as tk #you can do 'from tkinter import *', any is fine
btn = tk.Button(text = "Centered Button")
btn.place(relx=0.5, rely=0.5, anchor='center')