Traceback (most recent call last):    
File"..."...in <module>  
app = App(root)  
TypeError: object.__new__() takes no parameters

from tkinter import *
from ScaleAndOffsetConverter import *

class App():
    def __init_(self, master):

        self.c_var = DoubleVar()
        self.t_conv.ScaleAndOffsetConverter("F","C", 1.8, 32)
        frame = Frame(master)
        frame.pack()
        L1 = Label(frame, textvariable = self.result_var)
        L2 = Label(frame, text ="Deg C")
        E = Entry(frame, textvariable=self.c_var)
        L3 = Label( frame, text ="Deg F")
        B = Button(frame, text ="convert", command = self.convert)
        L1.grid(row=1,column=1)
        L2.grid(row=1, column=0)
        E.grid(row=0, column=1)
        L3.grid(row=0,column=0)
        B.grid(row=2, columnspan=2)
        self.result_var = DoubleVar

     def convert(self):
           c = self.c_var.get()
           self.result_var.set(self.t_conv.convert(c))

root = Tk()
app = App(root)
root.wm_title("Temp Converter")
root.mainloop()