Python GUI Calculator backspace and clear - python-3.x

Question

I'm making a simple calculator using tkinter. I have managed to get everything to work except for my backsapce and clear buttons.The error message I get is: 'TypeError: backspace() takes 0 positional arguments but 1 was given' for backspace and 'TypeError: clear() takes 0 positional arguments but 1 was given' for clear. I have looked around online tutorials but most of the tutorial I've found don't seem to have this problem.
from tkinter import *
root = Tk()
root.geometry("275x300")
root.title("Calculator")
def calculatorTitle():
labelTitle=Label(root, text="Calculator", bg = "black", fg = "white")
labelTitle.config(font = ("Verdana", 12, "bold"))
labelTitle.grid(row=0, column=0, columnspan=4, padx=55, pady=5)
e=Entry(root,width=20,font="Arial 12",justify='right', bg='yellow', fg = 'blue')
e.grid(row=1,column=0,columnspan=4, pady = 5)
def addEntry(ch):
e.insert(20, ch)
def CalculateEntry(expression):
expression = e.get()
expression = eval(expression)
e.delete(0, END)
e.insert(20, expression)
def clear():
e.delete(0, END)
return
def backspace():
current = e.get()
lenght = len(current)-1
e.delete(lenght, END)
def calculatorBoard():
b1=Button(root,text='1',width=5,command=lambda:addEntry(1))
b2=Button(root,text='2',width=5,command=lambda:addEntry(2))
b3=Button(root,text='3',width=5,command=lambda:addEntry(3))
bAddition=Button(root,text='+',width=5,command=lambda:addEntry('+'))
b4=Button(root,text='1',width=5,command=lambda:addEntry(4))
b5=Button(root,text='5',width=5,command=lambda:addEntry(5))
b6=Button(root,text='6',width=5,command=lambda:addEntry(6))
bSubtract=Button(root,text='-',width=5,command=lambda:addEntry('-'))
b7=Button(root,text='7',width=5,command=lambda:addEntry(7))
b8=Button(root,text='8',width=5,command=lambda:addEntry(8))
b9=Button(root,text='9',width=5,command=lambda:addEntry(9))
bMultiply=Button(root,text='*',width=5,command=lambda:addEntry('*'))
bClear=Button(root,text='CE',width=5,command=lambda:clear('CE'))
b0=Button(root,text='0',width=5,command=lambda:addEntry(0))
bBackspace=Button(root,text='<-',width=5,command=lambda:backspace('<-'))
bDivide=Button(root,text='/',width=5,command=lambda:addEntry('/'))
bEqual=Button(root,text='=',width=27,command=lambda:CalculateEntry('='))
b1.grid(row=2,column=0,pady = 10 )
b2.grid(row=2,column=1,pady = 10 )
b3.grid(row=2,column=2,pady = 10 )
bAddition.grid(row=2,column=3,pady = 10 )
b4.grid(row=3,column=0,pady = 10 )
b5.grid(row=3,column=1,pady = 10 )
b6.grid(row=3,column=2,pady = 10 )
bSubtract.grid(row=3,column=3,pady = 10 )
b7.grid(row=4,column=0,pady = 10 )
b8.grid(row=4,column=1,pady = 10 )
b9.grid(row=4,column=2,pady = 10 )
bMultiply.grid(row=4,column=3,pady = 10 )
bClear.grid(row=5,column=0,pady = 10 )
b0.grid(row=5,column=1,pady = 10 )
bBackspace.grid(row=5,column=2,pady = 10 )
bDivide.grid(row=5,column=3,pady = 10 )
bEqual.grid(row= 6, column= 0, columnspan= 4, pady= 10)
calculatorTitle()
calculatorBoard()
root.mainloop()
Edit: This part if an assignment where I have to follow some instructions.

Answer 1

def clear() and def backspace(): you define the functions with zero arguments.
clear('CE') and backspace('<-'): You call the functions with one argument
To fix the problem, either redefine the functions to take an argument,
def clear(arg):
# do whatever
def backspace(arg):
# do whatever
or change the call to not pass any.
bClear=Button(root,text='CE',width=5,command=clear)
bBackspace=Button(root,text='<-',width=5,command=backspace)
Be sure not to do both -- you'll run into the opposite problem.