Calculator in python

Question

I am trying to make calculator that can solve expressions with basic 4 operators, like 1+2*3-4/5, however it does not work and I do not know what is wrong. Please check my code.

Answer 1

Here is a simple python calculator program, feel free to use it:

#Python calculator

def menu():
    print ("Welcome to calculator.py")
    print ("your options are:")
    print (" ")
    print ("1) Addition")
    print ("2) Subtraction")
    print ("3) Multiplication")
    print ("4) Division")
    print ("5) Quit calculator.py")
    print (" ")
    return input ("Choose your option: ")

def add(a,b):
    print (a, "+", b, "=", a + b)

def sub(a,b):
    print (b, "-", a, "=", b - a)

def mul(a,b):
    print (a, "*", b, "=", a * b)

def div(a,b):
    print (a, "/", b, "=", a / b)

loop = 1
choice = 0
while loop == 1:
    choice = menu()
    if choice == 1:
        add(input("Add this: "),input("to this: "))
    elif choice == 2:
        sub(input("Subtract this: "),input("from this: "))
    elif choice == 3:
        mul(input("Multiply this: "),input("by this: "))
    elif choice == 4:
        div(input("Divide this: "),input("by this: "))
    elif choice == 5:
        loop = 0

print ("Thank you for using calculator.py!")