Centralizar a janela - samur2d2/Python GitHub Wiki

import tkinter as tk    

def Centralizar(win):
    win.update_idletasks()

    width = win.winfo_width()
    frm_width = win.winfo_rootx() - win.winfo_x()
    win_width = width + 2 * frm_width

    height = win.winfo_height()
    titlebar_height = win.winfo_rooty() - win.winfo_y()
    win_height = height + titlebar_height + frm_width

    x = win.winfo_screenwidth() // 2 - win_width // 2
    y = win.winfo_screenheight() // 2 - win_height // 2

    win.geometry('{}x{}+{}+{}'.format(width, height, x, y-25))

    win.deiconify()

main_app = tk.Tk()
main_app.minsize(1080, 640)
Centralizar(main_app)

main_app.mainloop()