Basic calculator made with python...

So basically made this calculator by using If , Else and Elif conditions in Python...

while(True):
    print("Actions available\n('+','-','*','**','/')")
    a=int(input("Enter your first number\n"))
    sign=input("Enter operator\n")
    b=int(input("Enter your second number\n"))

    if sign=='+':
        print("Your addition is",a+b)
    elif sign=='-':
        print("Your subtraction is",a-b)
    elif sign=='/':
        print("Your division is", a / b)
    elif sign=='*':
        print("Your multiplication is", a * b)
    elif sign=='**':
        print("Your power is", a ** b)
    else:
        print("Error! Unexpected sign or values")
    opinion=input("For using this calculator again enter yes and for exit press enter or type exit\n")
    opinion.upper()
    if opinion=="yes":
        continue
    else:
        print("Thanks for using this calculator")
        break

I have also made a calculator which works perfectly but is a risky calculator because it gives wrong or pre set answer for some specific values..

print("This is a risky calculator")
x=int(input("Enter first number:"))
sign=input("Enter your function:")
y=int(input("Enter the second number:"))

if sign=='-':
    if x==10 and y==5:
        print("Your subtraction is",6)
    else:
        print("Your subtraction is", (x) - (y))
elif sign=='+':
    if x==56 and y==9 :
        print("Your addition is",77)
    else:
        print("Your addition is", (x) + (y))

elif sign=='*':
    if x==45 and y==3 :
        print("Your multiplication is",555)
    else:
        print("Your multiplication is", (x) * (y))

elif sign=='/':
    if x==56 and y==6 :
        print("Your division is",4)
    else:
        print("Your division is", (x) / (y))
else:
    print("Error! Unexpected sign or values")

print("How many marks you got after using this calculator")

You can also run this code and do some basic calculations and I have 

also used while(True) functions by user's choice to run this program again

and again..