import tkinter as tk
base=tk.Tk()
button1=tk.Button(base,text="push1",width=30)
button2=tk.Button(base,text="push2",width=15)
button3=tk.Button(base,text="push3",width=15)
button4=tk.Button(base,text="push4",width=30)
button1.pack()
button2.pack(side=tk.LEFT)
button3.pack(side=tk.RIGHT)
button4.pack()
base.mainloop()