I'm trying to make a GUI application of calculator using tkinter. I made a widget class that inherits from tkinter.Frame, in which I have a variable display_string(tkinter.StringVar) which contains the string to be displayed on the calculator string. I am not able to set any value to this variable by set(). Can someone please explain me what's wrong? I'm getting the following error on line 13.
TypeError: set() missing 1 required positional argument: 'value'
I followed this code example from the book "Python - GUI programming tkinter" from Alan D. Moore which worked fine.
Reference
import tkinter as tk
from tkinter import ttk
class HelloView(tk.Frame):
def __init__(self, parent, *args, **kwargs):
super().__init__(parent, *args, **kwargs)
self.name = tk.StringVar()
self.hello_string = tk.StringVar()
#--------------------------------
self.hello_string.set("Hello World")
#-------------------------------------
name_label = ttk.Label(self, text="Name: ")
name_entry = ttk.Entry(self, textvariable=self.name)
change_button = ttk.Button(self, text="Change", command=self.on_change)
hello_label = ttk.Label(self, textvariable=self.hello_string,
font=("TkDefaultFont", 64), wraplength=600)
# Layout form
name_label.grid(row=0, column=0, sticky=tk.W)
name_entry.grid(row=0, column=1, sticky=(tk.W + tk.E))
change_button.grid(row=0, column=2, sticky=(tk.E))
hello_label.grid(row=1, column=0, columnspan=3)
self.columnconfigure(1, weight=1)
def on_change(self):
if self.name.get().strip():
self.hello_string.set("Hello " + self.name.get())
else:
self.hello_string.set("Hello World")
class MyApplication(tk.Tk):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# set the window properties
self.title("Hello Tkinter")
self.geometry("800x300")
self.resizable(width=False, height=False)
# define the ui
HelloView(self).grid(sticky=(tk.E + tk.W + tk.N + tk.S))
self.columnconfigure(0, weight=1)
if __name__ == '__main__':
app = MyApplication()
app.mainloop()
My Code
import tkinter as tk
from tkinter import ttk
class CalcView(tk.Frame):
def __init__(self, parent, *args, **kwargs):
super().__init__(parent, *args, **kwargs)
self.display_string = tk.StringVar
self.disp_ans = tk.IntVar
self.operand1 = tk.IntVar
self.operand2 = tk.IntVar
self.operation = self.output
# Here's the error:#---------------------------------------
self.display_string.set("Hey")
##-----------------------------------------------------------
display_label = ttk.Label(self, textvariable = self.display_string)
button1 = ttk.Button(self, text = '7', command = self.add_seven)
button2 = ttk.Button(self, text = '8', command = self.add_eight)
button3 = ttk.Button(self, text = '9', command = self.add_nine)
button4 = ttk.Button(self, text = '4', command = self.add_four)
button5 = ttk.Button(self, text = '5', command = self.add_five)
button6 = ttk.Button(self, text = '6', command = self.add_six)
button7 = ttk.Button(self, text = '1', command = self.add_one)
button8 = ttk.Button(self, text = '2', command = self.add_two)
button9 = ttk.Button(self, text = '3', command = self.add_three)
button10 = ttk.Button(self, text = '0', command = self.add_zero)
button11 = ttk.Button(self, text = 'C', command = self.clear)
button12 = ttk.Button(self, text = 'X', command = self.multiplication)
button13 = ttk.Button(self, text = '\\', command = self.division)
button14 = ttk.Button(self, text = '=', command = self.output)
button15 = ttk.Button(self, text = '+', command = self.addition)
button16 = ttk.Button(self, text = '-', command = self.subtraction)
display_label.grid(row = 0, columnspan = 4, sticky = (tk.E + tk.W))
button1.grid(row = 1, column = 0, sticky = (tk.E + tk.W))
button2.grid(row = 1, column = 1, sticky = (tk.E + tk.W))
button3.grid(row = 1, column = 2, sticky = (tk.E + tk.W))
button4.grid(row = 2, column = 0, sticky = (tk.E + tk.W))
button5.grid(row = 2, column = 1, sticky = (tk.E + tk.W))
button6.grid(row = 2, column = 2, sticky = (tk.E + tk.W))
button7.grid(row = 3, column = 0, sticky = (tk.E + tk.W))
button8.grid(row = 3, column = 1, sticky = (tk.E + tk.W))
button9.grid(row = 3, column = 2, sticky = (tk.E + tk.W))
button10.grid(row = 4, column = 0, sticky = (tk.E + tk.W))
button11.grid(row = 1, column = 3, sticky = (tk.E + tk.W))
button12.grid(row = 2, column = 3, sticky = (tk.E + tk.W))
button13.grid(row = 3, column = 3, sticky = (tk.E + tk.W))
button14.grid(row = 4, column = 3, sticky = (tk.E + tk.W))
button15.grid(row = 4, column = 2, sticky = (tk.E + tk.W))
button16.grid(row = 4, column = 1, sticky = (tk.E + tk.W))
self.columnconfigure(0, weight = 1)
def add_nine(self):
pass#self.display_string.set(self.display_string.get() + '9')
def add_eight(self):
pass#self.display_string.set(self.display_string.get() + '8')
def add_seven(self):
pass#self.display_string.set(self.display_string.get() + '7')
def add_six(self):
pass#self.display_string.set(self.display_string.get() + '6')
def add_five(self):
pass#self.display_string.set(self.display_string.get() + '5')
def add_four(self):
pass#self.display_string.set(self.display_string.get() + '4')
def add_three(self):
pass#self.display_string.set(self.display_string.get() + '3')
def add_two(self):
pass#self.display_string.set(self.display_string.get() + '2')
def add_one(self):
pass#self.display_string.set(self.display_string.get() + '1')
def add_zero(self):
pass#self.display_string.set(self.display_string.get() + '0')
def clear(self):
pass
def multiplication(self):
pass
def division(self):
pass
def addition(self):
pass
def subtraction(self):
pass
def output(self):
pass
class MainApplication(tk.Tk):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.title("Calculator")
self.geometry("300x600")
self.resizable(width = False, height = False)
CalcView(self).grid(sticky = (tk.N + tk.S + tk.E + tk.W))
if __name__ == "__main__":
app = MainApplication()
app.mainloop()
