Napisałem kod kalkulatora z GUI w Tkinter. Wymyśliłem sobie, że pod literką C będę miał funkcję która będzie kasować ostatnią wpisaną cyfrę lub znak. Takie zwykłe cofnij. Próbowałem do tego wykorzystać .delete(END) ale coś ewidentnie robię nie tak.
Poniżej wklejam cały kod. Funkcja która mnie interesuje ma nazwę Cancel. Będę wdzięczny za pomoc.
import sys
from tkinter import *
calculator = Tk()
calculator.title("Calculator by Grzego")
calculator.resizable(0, 0)
class Application(Frame):
def __init__(self, master, *args, **kwargs):
Frame.__init__(self, master, *args, **kwargs)
self.CreateWidgets()
def Calculation(self):
self.calculation = self.display.get()
self.calculation = self.calculation.replace("%", "/100")
try:
self.result = eval(self.calculation)
self.Replace(self.result)
except:
messagebox.showinfo("Error", "Invalid input")
def Replace(self, text):
self.display.delete(0, END)
self.display.insert(0, text)
def Append(self, text):
self.entryText = self.display.get()
self.textLenght = len(self.entryText)
if self.entryText == "0":
self.Replace(text)
else:
self.display.insert(self.textLenght, text)
def Cancel(self):
self.entryText.delete(END)
def Clear(self):
self.Replace("0")
def CreateWidgets(self):
self.display = Entry(self, font=("Helvetica", 16), borderwidth=0, relief=RAISED, justify=RIGHT)
self.display.insert(0, "0")
self.display.grid(row=0, column=0, columnspan=5)
self.Seven = Button(self, font=("Helvetica", 11), text="7", borderwidth=1, command=lambda: self.Append("7"))
self.Seven.grid(row=1, column=0, sticky="NWNESWSE")
self.Eight = Button(self, font=("Helvetica", 11), text="8", borderwidth=1, command=lambda: self.Append("8"))
self.Eight.grid(row=1, column=1, sticky="NWNESWSE")
self.Nine = Button(self, font=("Helvetica", 11), text="9", borderwidth=1, command=lambda: self.Append("9"))
self.Nine.grid(row=1, column=2, sticky="NWNESWSE")
self.Percent = Button(self, font=("Helvetica", 11), text="%", borderwidth=1, command=lambda: self.Append("%"))
self.Percent.grid(row=1, column=3, sticky="NWNESWSE")
self.Plus = Button(self, font=("Helvetica", 11), text="+", borderwidth=1, command=lambda: self.Append("+"))
self.Plus.grid(row=1, column=4, sticky="NWNESWSE")
self.Four = Button(self, font=("Helvetica", 11), text="4", borderwidth=1, command=lambda: self.Append("4"))
self.Four.grid(row=2, column=0, sticky="NWNESWSE")
self.Five = Button(self, font=("Helvetica", 11), text="5", borderwidth=1, command=lambda: self.Append("5"))
self.Five.grid(row=2, column=1, sticky="NWNESWSE")
self.Six = Button(self, font=("Helvetica", 11), text="6", borderwidth=1, command=lambda: self.Append("6"))
self.Six.grid(row=2, column=2, sticky="NWNESWSE")
self.Multiply = Button(self, font=("Helvetica", 11), text="*", borderwidth=1, command=lambda: self.Append("*"))
self.Multiply.grid(row=2, column=3, sticky="NWNESWSE")
self.Minus = Button(self, font=("Helvetica", 11), text="-", borderwidth=1, command=lambda: self.Append("-"))
self.Minus.grid(row=2, column=4, sticky="NWNESWSE")
self.One = Button(self, font=("Helvetica", 11), text="1", borderwidth=1, command=lambda: self.Append("1"))
self.One.grid(row=3, column=0, sticky="NWNESWSE")
self.Two = Button(self, font=("Helvetica", 11), text="2", borderwidth=1, command=lambda: self.Append("2"))
self.Two.grid(row=3, column=1, sticky="NWNESWSE")
self.Three = Button(self, font=("Helvetica", 11), text="3", borderwidth=1, command=lambda: self.Append("3"))
self.Three.grid(row=3, column=2, sticky="NWNESWSE")
self.Divide = Button(self, font=("Helvetica", 11), text="/", borderwidth=1, command=lambda: self.Append("/"))
self.Divide.grid(row=3, column=3, sticky="NWNESWSE")
self.Equal = Button(self, font=("Helvetica", 11), text="=", borderwidth=1, command=lambda: self.Calculation())
self.Equal.grid(row=3, column=4, rowspan=2, sticky="NWNESWSE")
self.Cancel = Button(self, font=("Helvetica", 11), text="C", borderwidth=1, command=lambda: self.Cancel)
self.Cancel.grid(row=4, column=0, sticky="NWNESWSE")
self.Zero = Button(self, font=("Helvetica", 11), text="0", borderwidth=1, command=lambda: self.Append("0"))
self.Zero.grid(row=4, column=1, sticky="NWNESWSE")
self.Clear = Button(self, font=("Helvetica", 11), text="CE", borderwidth=1, command=self.Clear)
self.Clear.grid(row=4, column=2, sticky="NWNESWSE")
self.Dot = Button(self, font=("Helvetica", 11), text=".", borderwidth=1, command=lambda: self.Append("."))
self.Dot.grid(row=4, column=3, sticky="NWNESWSE")
app = Application(calculator).grid()
calculator.mainloop()
tkinter 
Python 