What is the correct way to use a variable from another function?

Question

def addition(number, number2, mathematic_assignment):
    sum_value = number + number2
    return f'The sum of {number} {mathematic_assignment} {number2} is {sum_value}'


def subtraction(number, number2, mathematic_assignment):
    subtract_value = number - number2
    return f'The subtraction of {number} {mathematic_assignment} {number2} is {subtract_value}'


def multiply(number, number2, mathematic_assignment):
    multiplied_value = number * number2
    return f'The result of multiplying {number} {mathematic_assignment} {number2} is {multiplied_value}'


def division(number, number2, mathematic_assignment):
    divided_value = number / number2
    return f'The division of {number} {mathematic_assignment} {number2} is {round(divided_value)}'


def run_program():
    print("Welcome to the base calculator")
    is_running = True
    while is_running:
        first_number = int(input('Please provide the first number: '))
        second_number = int(input('Please provide the second number: '))
        mathematic_assignment = input('Please provide mathematical preference: \n+\n-\n*\n/\n')
        if mathematic_assignment == '+':
            print(addition(first_number, second_number, mathematic_assignment))
        elif mathematic_assignment == '-':
            print(subtraction(first_number, second_number, mathematic_assignment))
        elif mathematic_assignment == '*':
            print(multiply(first_number, second_number, mathematic_assignment))
        elif mathematic_assignment == '/':
            print(division(first_number, second_number, mathematic_assignment))
        else:
            print('There can be an error in the output, you must only put in "+", "-", "*", "/"')

        choice = input("Press 'q' to quit or anything to go on: ")
        if choice == 'q':
            print('The program will now quit')enter code here
            is_running = False


if __name__ == '__main__':
    run_program()enter code here

The following code is an example of a base calculator made out of functions. However, the problem I have been struggling with is starting the calculator where the first number is the previous result, so you only get the second number and the mathematical operation required (so if 5+5 is 10 then the next time you run the code (using the while loop) now the first number is 10 + {another number}).

As you can see it's all ready except the following challenge. I am more than sure I can tackle this on my own without the functions however I want to know how functions operate and learn them in more detail. I would really appreciate an answer

score 1 · Answer 1 · answered Jul 04 '21 at 10:25

First the computing method should return the numeric value, so you can use it later, I removed parameter mathematic_assignment as every method knows its own

def addition(number, number2):
    sum_value = number + number2
    return sum_value, f'The sum of {number} + {number2} is {sum_value}'
def subtraction(number, number2):
    subtract_value = number - number2
    return subtract_value, f'The subtraction of {number} - {number2} is {subtract_value}'
def multiply(number, number2):
    multiplied_value = number * number2
    return multiplied_value, f'The result of multiplying {number} * {number2} is {multiplied_value}'
def division(number, number2):
    divided_value = number / number2
    return divided_value, f'The division of {number} / {number2} is {round(divided_value)}'

Then in the main code, you may

save the result of each call
ask whether to use or not the previous result, if it exists (you could also not ask and use it automatically if it exists)

def run_program():
    numeric_result = None
    print("Welcome to the base calculator")
    while True:
        result = None
        if numeric_result:
            first_number = input(
                f'Please provide the first number or empty to use the previous result ({numeric_result}):')
            first_number = int(first_number) if first_number else numeric_result
        else:
            first_number = int(input('Please provide the first number: '))

        second_number = int(input('Please provide the second number: '))
        mathematic_assignment = input('Please provide mathematical preference: + - * / : ')

        if mathematic_assignment == '+':
            result = addition(first_number, second_number)
        elif mathematic_assignment == '-':
            result = subtraction(first_number, second_number)
        elif mathematic_assignment == '*':
            result = multiply(first_number, second_number)
        elif mathematic_assignment == '/':
            result = division(first_number, second_number)
        else:
            print('There can be an error in the output, you must only put in "+", "-", "*", "/"')

        if result:
            numeric_result, str_result = result
            print(str_result)

        choice = input("Press 'q' to quit or anything to go on: ")
        if choice == 'q':
            print('The program will now quit')
            break

Here's a sample run

Welcome to the base calculator
Please provide the first number: 5
Please provide the second number: 5
Please provide mathematical preference: + - * / : +
The sum of 5 + 5 is 10
Press 'q' to quit or anything to go on:
Please provide the first number or empty to use the previous result (10):
Please provide the second number: 5
Please provide mathematical preference: + - * / : *
The result of multiplying 10 * 5 is 50
Press 'q' to quit or anything to go on:
Please provide the first number or empty to use the previous result (50):12
Please provide the second number: 12
Please provide mathematical preference: + - * / : -
The subtraction of 12 - 12 is 0
Press 'q' to quit or anything to go on: q
The program will now quit

What is the correct way to use a variable from another function?

1 Answers1