### Simple Calculator Program in Python 3 :

In this tutorial, we will learn how to create a Calculator using python 3. We are going to create only a simple calculator that can perform *addition, subtraction, multiplication and division* . You can add any other mathematical operations to it if you want.

Before going through the code, let me show you how it is going to work :

### Algorithm we are using in this program :

1. We are using one infinite loop to get input from user *continuously*. That means, user can use the calculator as many time as he wants.

2. Calculator will exit if user will enter ‘q’ as input

3. For each calculation (add, subtract, multiply, divide) we have different functions.

4. Using ‘if-else’ condition, we are checking what type of calculation user wants to do.

### Program :

print ("Welcome !!") #function to add two numbers def add(first_num,second_num): print ("{} + {} = {}".format(first_num,second_num,first_num + second_num)) #function to substract one number from another def sub(first_num,second_num): print ("{} - {} = {}".format(first_num,second_num,first_num - second_num)) #function to multiply two numbers def mul(first_num,second_num): print ("{} * {} = {}".format(first_num,second_num,first_num * second_num)) #function for division def div(first_num,second_num): print ("{}/{} = {}".format(first_num,second_num,first_num/second_num)) print (''' Enter + for addition Enter - for Substraction Enter * for multiplication Enter / for Division Enter q to Quit the program ''') while True : print("") user_input = input ("Enter calculator type : ") if user_input == '+' : print ("To calculate (number 1 + number 2) :") add(int(input("Enter number 1 : ")),int(input("Enter number 2 : "))) elif user_input == '-': print ("To calculate (number 1 - number 2) :") sub(int(input("Enter number 1 : ")), int(input("Enter number 2 : "))) elif user_input == '*': print ("To calculate (number 1 * number 2) :") mul(int(input("Enter number 1 : ")), int(input("Enter number 2 : "))) elif user_input == '/': print ("To calculate (number 1 / number 2) :") div(int(input("Enter number 1 : ")), int(input("Enter number 2 : "))) elif user_input == 'q': break print ("") else: print ("Please Enter a Valid Input !!")

### Sample Output :

Welcome !! Enter + for addition Enter - for Substraction Enter * for multiplication Enter / for Division Enter q to Quit the program Enter calculator type : + To calculate (number 1 + number 2) : Enter number 1 : 12 Enter number 2 : 14 12 + 14 = 26 Enter calculator type : - To calculate (number 1 - number 2) : Enter number 1 : 44 Enter number 2 : 9 44 - 9 = 35 Enter calculator type : * To calculate (number 1 * number 2) : Enter number 1 : 123 Enter number 2 : 4 123 * 4 = 492 Enter calculator type : / To calculate (number 1 / number 2) : Enter number 1 : 123 Enter number 2 : 3 123/3 = 41.0 Enter calculator type : 1 Please Enter a Valid Input !!

### Add more Actions to this calculator :

You can add more actions to this calculator program. Just add more functions for each type of calculations and add more if-elif conditions. *Happy Coding ðŸ™‚*