from Tkinter import *
import tkFileDialog, tkMessagebox
 
class App:
 
def __init__(self, master):
    self.master = master
 
    #call start to initialize to create the UI elemets
    self.start()
 
def start(self):
    self.master.title("This is the title of the 'Window'")
 
    self.now = datetime.datetime.now()
 
    #CREATE A TEXT/LABEL
    #create a variable with text
    label01 = "This is some text"
    #put "label01" in "self.master" which is the window/frame
    #then, put in the first row (row=0) and in the 2nd column (column=1), align it to "West"/"W"
    Label(self.master, text=label01).grid(row=0, column=0, sticky=W)
 
    #CREATE A TEXTBOX
    self.filelocation = Entry(self.master)
    self.filelocation["width"] = 60
    self.filelocation.focus_set()
    self.filelocation.grid(row=1,column=0)
 
    #CREATE A BUTTON WITH "ASK TO OPEN A FILE"
    self.open_file = Button(self.master, text="Browse...", command=self.browse_file) #see: def browse_file(self)
    self.open_file.grid(row=1, column=1) #put it beside the filelocation textbox
 
    #CREATE RADIO BUTTONS
    RADIO_BUTTON = [
        ("This will display A", "A"),
        ("This will display B","B")
    ]
 
    #initialize a variable to store the selected value of the radio buttons
    #set it to A by default
    self.radio_var = StringVar()
    self.radio_var.set("A")
 
    #create a loop to display the RADIO_BUTTON
    i=0
    for text, item in RADIO_BUTTON:
        #setup each radio button. variable is set to the self.radio_var
        #and the value is set to the "item" in the for loop
        self.radio = Radiobutton(self.master, text=text, variable=radio_var, value=item)
        self.radio.grid(row=2, column=i)
        i += 1
 
    #now for a button
    self.submit = Button(self.master, text="Execute!", command=self.start_processing, fg="red")
    self.submit.grid(row=3, column=0)
 
def start_processing(self):
    #more code here
 
def browse_file(self):
    #put the result in self.filename
    self.filename = tkFileDialog.askopenfilename(title="Open a file...")
 
    #this will set the text of the self.filelocation
    self.filelocation.insert(0,self.filename)
root = Tk()
app = App(root)
root.mainloop()