tkinter Entry.configure() code example
Example 1: write in entry() in tkinter
from Tkinter import *
master = Tk()
e = Entry(master)
e.pack()
e.focus_set()
def callback():
print e.get()
b = Button(master, text="get", width=10, command=callback)
b.pack()
mainloop()
Example 2: write in entry() in tkinter
v = StringVar()
e = Entry(master, textvariable=v)
e.pack()
v.set("a default value")
s = v.get()