Python calculator gui

from tkinter import*

def btnClick(number):
    global operator
    operator=operator + str(number)
    text_Input .set(operator)

def btnclearDisplay():
    global operator
    operator=""
    text_Input.set("")

def btnEqualsInput():
    global operator
    sumup=str(eval(operator))
    text_Input.set(sumup)
    operator=""

cal = Tk()
cal.title("Calculater")
operator =""
text_Input = StringVar()
textDisplay = Entry(cal,font=('aril', 20 , 'bold') , textvariable=text_Input, bd=30, insertwidth=4,
                    bg ="powder blue" , justify='right').grid(columnspan=4)
#======================================================================================================#
btn7=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="7",bg ="powder blue",command=lambda:btnClick(7)).grid(row=1,column=0)
btn8=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="8",bg ="powder blue",command=lambda:btnClick(8)).grid(row=1,column=1)
btn9=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="9",bg ="powder blue",command=lambda:btnClick(9)).grid(row=1,column=2)
Addition=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="+",bg ="powder blue",command=lambda:btnClick('+')).grid(row=1,column=3)
#========================================================================================================#
btn4=Button(cal,padx=16,pady=16 ,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="4",bg ="powder blue",command=lambda:btnClick(4)).grid(row=2,column=0)
btn5=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="5",bg ="powder blue",command=lambda:btnClick(5)).grid(row=2,column=1)
btn6=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="6",bg ="powder blue",command=lambda:btnClick(6)).grid(row=2,column=2)
Subtraction=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="-",bg ="powder blue",command=lambda:btnClick('-')).grid(row=2,column=3)
#=======================================================================================================#
btn1=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="1",bg ="powder blue",command=lambda:btnClick(1)).grid(row=3,column=0)
btn2=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="2",bg ="powder blue",command=lambda:btnClick(2)).grid(row=3,column=1)
btn3=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="3",bg ="powder blue",command=lambda:btnClick(3)).grid(row=3,column=2)
Addition=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="*",bg ="powder blue",command=lambda:btnClick('*')).grid(row=3,column=3)
#========================================================================================================#
btn0=Button(cal,padx=16,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="0",bg ="powder blue",command=lambda:btnClick(0)).grid(row=4,column=0)
btnclear=Button(cal,padx=16,pady=16 ,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="C",bg ="powder blue",command=btnclearDisplay).grid(row=4,column=1)
btnEqual=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="=",bg ="powder blue",command=btnEqualsInput).grid(row=4,column=2)
Division=Button(cal,padx=16 ,pady=16,bd=8, fg ="black", font=('arial', 20 , 'bold'),
            text="/",bg ="powder blue",command=lambda:btnClick("/")).grid(row=4,column=3)



cal.mainloop()