Simple python calculator for beginners

So I have been seeing a lot of calculator games examples on different platforms , for beginners like me its always very confusing. In beginner basic mode we have a clear understanding of variables, lists, input, for loop and conditions.

So I have made a very simple calculator game in python using simple basic beginner level data types in Python.

#simple calculator beginner level
#set1 for working with two values
#set3 for working with three values

sets = "set1","set2"

set1 = "num1+num2","num1-num2","num1*num2"
set2 = "num1+num2+num3","num1*num2*num3"

choose = str(input("Enter your set here:"))

if choose == "set1":
    action = str(input("Add(a), Sub(s), Mult(m), Div(d)"))
    num1 = int(input("Enter your number here:"))
    num2 = int(input("Enter your number here:"))
    if action == "a":
        print("Addition is:",num1+num2)
    elif action == "s":
        print("Subtraction is:",num1-num2)
    elif action == "m":
        print("Multiplication is:",num1*num2)
    elif action == "d":
        print("Division is:",num1/num2)
    else:
        print("over")

#set2
if choose == "set2":
    action = str(input("Add(a), Mult(m)"))
    num1 = int(input("Enter your number here:"))
    num2 = int(input("Enter your number here:"))
    num3 = int(input("Enter your number here:"))
    if action == "a":
        print("Addition is:",num1+num2+num3)
    elif action == "m":
        print("Multiplication is:",num1*num2*num3)
    else:
        print("over")

I have used two sets to work with two values and three values. In both sets I have added simple calculator mechanism. The variable “action” is given those values and in both sets “action” is tested against conditions.

As in set1 Addition, Subtraction, Multiplication, Division are added. In set2 Addition and Multiplication for three values are added.