packを使う場合
Python
1import tkinter as tk
2root = tk.Tk()
3label = tk.Label(root, text="中心")
4label.pack(anchor='center',expand=1)
5root.mainloop()
gridを使う場合
Python
1import tkinter as tk
2root = tk.Tk()
3label = tk.Label(root, text="中心")
4label.grid(0,0)
5root.grid_columnconfigure(0, weight=1)
6root.grid_rowconfigure(0, weight=1)
7root.mainloop()