python 单选框radiobutton

"create a group of radio buttons that launch dialog demos"

from tkinter import * # get base widget set
from dialogTable import demos # button callback handlers
from quitter import Quitter # attach a quit object to "me"

class Demo(Frame):
def init(self, parent=None, **options):
Frame.init(self, parent, **options)
self.pack()
Label(self, text="Radio demos").pack(side=TOP)
self.var = StringVar()
for key in demos:
Radiobutton(self, text=key,
command=self.onPress,
variable=self.var,
value=key).pack(anchor=NW)
self.var.set(key) # select last to start
Button(self, text='State', command=self.report).pack(fill=X)
Quitter(self).pack(fill=X)

def onPress(self):
    pick = self.var.get()
    print('you pressed', pick)
    print('result:', demos[pick]())

def report(self):
    print(self.var.get())

if name == 'main': Demo().mainloop()