Setting and Retrieving Data with TkInter - python-2.7

Question

I just ran into some strange behavior that has me stumped. I'm writing a simple little GUI for some in-house data processing. I want to allow a user to switch between a few different data-processing modes and input some parameters which define how the data is processed for each mode. The problem is that when the user inputs new parameters, the app ignores requests to switch modes.
The code below replicates the issue. I apologize for the size, this was the shortest code that replicates the problem.
import Tkinter as Tk
class foo(Tk.Frame):
def __init__(self):
self.master = master =Tk.Tk()
Tk.Frame.__init__(self,self.master) #Bootstrap
#Here mode and parameters as key, value pairs
self.data = {'a':'Yay',
'b':'Boo'
}
self.tex = Tk.Text(master=master)
self.tex.grid(row=0,column=0,rowspan=3,columnspan=4)
self.e = Tk.Entry(master=master)
self.e.grid(row=3,column=0,columnspan=4)
self.sv =Tk.StringVar()
self.sv.set('a')
self.b1 = Tk.Radiobutton(master=master,
text = 'a',
indicatoron = 0,
variable = self.sv,
value = 'a')
self.b2 = Tk.Radiobutton(master=master,
text = 'b',
indicatoron = 0,
variable = self.sv,
value = 'b')
self.b3 = Tk.Button(master = master,
text='Apply',command=self.Apply_Func)
self.b4 = Tk.Button(master = master,
text='Print',command=self.Print_Func)
self.b1.grid(row=4,column=0)
self.b2.grid(row=4,column=1)
self.b3.grid(row=4,column=2)
self.b4.grid(row=4,column=3)
def Apply_Func(self):
self.innerdata = self.e.get()
def Print_Func(self):
self.tex.insert(Tk.END,str(self.innerdata)+'\n')
#This is how I'm retrieving the user selected parameters
#property
def innerdata(self):
return self.data[self.sv.get()]
#And how I'm setting the user defined parameters
#innerdata.setter
def innerdata(self,value):
self.data[self.sv.get()] = value
if __name__ == "__main__":
app = foo()
app.mainloop()
Expected behavior:
1) Press button 'a' then 'print' prints:
Yay
2) Press button 'b' then 'print' prints:
Boo
3) Type 'Zep Rocks' into the entry field and press apply
4) Pressing 'print' now yields
Zep Rocks
5) Pressing 'a' then 'print' should yield
Yay
But instead yields
Zep Rocks
Which might be true, but not desired right now. What is going on here?
Edit: I have some new information. Tk.Frame in python 2.7 is not a new-style class. It isn't friendly with descriptors, so rather than interpreting the '=' as a request to use the foo.innerdata's __set__ method, it just assigns the result of self.e.get() to innerdata.
ARGLEBARGLE!!!
Still an open question: how do I get this to do what I want in a clean manner?

Answer 1

So the core problem is that Tk.Frame doesn't subclass from object, so it is not a new-style python class. Which means it doesn't get down with descriptors like I was trying to use. One solution that I found is to subclass my app from object instead.
Code that solves my problem is below:
import Tkinter as Tk
class foo(object):
def __init__(self,master):
self.master = master #Bootstrap
self.mainloop = master.mainloop
self.data = {'a':{'value':7,'metavalue':False},
'b':{'value':'Beeswax','metavalue':True}
}
self.tex = Tk.Text(master=master)
self.tex.grid(row=0,column=0,rowspan=3,columnspan=4)
self.e = Tk.Entry(master=master)
self.e.grid(row=3,column=0,columnspan=4)
self.sv =Tk.StringVar()
self.sv.set('a')
self.b1 = Tk.Radiobutton(master=master,
text = 'a',
indicatoron = 0,
variable = self.sv,
value = 'a')
self.b2 = Tk.Radiobutton(master=master,
text = 'b',
indicatoron = 0,
variable = self.sv,
value = 'b')
self.b3 = Tk.Button(master = master,text='Apply',command=self.Apply_Func)
self.b4 = Tk.Button(master = master,text='Print',command=self.Print_Func)
self.b1.grid(row=4,column=0)
self.b2.grid(row=4,column=1)
self.b3.grid(row=4,column=2)
self.b4.grid(row=4,column=3)
def Apply_Func(self):
self.innerdata = self.e.get()
def Print_Func(self):
self.tex.insert(Tk.END,str(self.innerdata)+'\n')
#property
def innerdata(self):
return self.data[self.sv.get()]
#innerdata.setter
def innerdata(self,value):
self.data[self.sv.get()] = value
if __name__ == "__main__":
master = Tk.Tk()
app = foo(master)
app.mainloop()