Python3: If elif else with while loops in a function

Question

I am quite confused about what is wrong with my code. I am trying to make a math practice program. However, when I choose an operation, no matter what I type in, it will always take me to addition. Can someone please help me solve this problem. My little brother is not very excitedly waiting. :)

from random import randint
print("Welcome to Luke's Math Practice")
score = 0

def mathAddition():
    global score
    numberOne = randint(0, 100)
    numberTwo = randint(0, 100)
    answer = input(f"{numberOne} + {numberTwo} = ")
    correctAnswer = numberOne + numberTwo
    if int(answer) == correctAnswer:
        print("Correct!")
        score = score + 1
    elif int(answer) != correctAnswer:
        print("Incorrect!")
        print("The Correct Answer was", correctAnswer)
        print("Your Score Is:", score)
        choiceOperation()
    else:
        print("Sorry That Was an Invalid Answer")

def mathSubtraction():
    global score
    numberOne = randint(0, 100)
    numberTwo = randint(0, 100)
    answer = input(f"{numberOne} - {numberTwo} = ")
    correctAnswer = numberOne - numberTwo
    if int(answer) == correctAnswer:
        print("Correct!")
        score = score + 1
    elif int(answer) != correctAnswer:
        print("Incorrect!")
        print("The Correct Answer was", correctAnswer)
        print("Your Score Is:", score)
        choiceOperation()
    else:
        print("Sorry That Was an Invalid Answer")

def mathMultiplication():
    global score
    numberOne = randint(0, 20)
    numberTwo = randint(0, 20)
    answer = input(f"{numberOne} * {numberTwo} = ")
    correctAnswer = numberOne * numberTwo
    if int(answer) == correctAnswer:
        print("Correct!")
        score = score + 1
    elif int(answer) != correctAnswer:
        print("Incorrect!")
        print("The Correct Answer was", correctAnswer)
        print("Your Score Is:", score)
        choiceOperation()
    else:
        print("Sorry That Was an Invalid Answer")

def mathDivision():
    global score
    numberOne = randint(0, 20)
    numberTwo = randint(0, 20)
    answer = input(f"{numberOne} / {numberTwo} = ")
    correctAnswer = numberOne / numberTwo
    if int(answer) == correctAnswer:
        print("Correct!")
        score = score + 1
    elif int(answer) != correctAnswer:
        print("Incorrect!")
        print("The Correct Answer was", correctAnswer)
        print("Your Score Is:", score)
        choiceOperation()
    else:
        print("Sorry That Was an Invalid Answer")

def choiceOperation():
    operationChoice = input("Would you like to practice adding, subtracting, multiplying, or dividing? ")
    if operationChoice == "add" or "+" or "adding" or "addition":
        while True:
            mathAddition()
    elif operationChoice == "subtract" or "-" or "subtracting" or "subtraction":
        while True:
            mathSubtraction()
    elif operationChoice == "multiply" or "*" or "x" or "multipying" or "multiplication":
        while True:
            mathMultiplication()
    elif operationChoice == "divide" or "/" or "dividing" or "division":
        while True:
            mathDivision()
    else:
        print("Sorry, That Was an Invalid Choice")

choiceOperation()

score 1 · Answer 1 · answered May 14 '17 at 01:49

Here's the problem, in your choinceOperation funtion. the if statemnts should looks like:

if operationChoice in ("add", "+", "adding", "addition"):

The reason why your codes always leads to "+" is that:

operationChoice == "add" or "+" or "adding" or "addition"
# (operationChoice == "add") or "+" or "adding" or "addition"
# and the first fails, but the "+" will always be True.

score 1 · Accepted Answer · answered May 14 '17 at 01:50

This line

if operationChoice == "add" or "+" or "adding" or "addition":

is not doing what you think it is doing. It is checking if operationChoice == "add" or if any of "+" or "adding" or "addition" evaluate to true. (All non-empty strings evaluate to True)

Either make it

if operationChoice in ("add", "+", "adding", "addition"):

OR

if operationChoice == "add" or operationChoice == "+" or operationChoice == "adding" or operationChoice == "addition":

score 1 · Answer 3 · edited May 23 '17 at 12:26

Use this and refer to here.

def choiceOperation():
    operationChoice = input("Would you like to practice adding, subtracting, multiplying, or dividing? ")
    if operationChoice in ['add', '+', 'adding', 'addition']:
        mathAddition()
    elif operationChoice in ['subtract', '-', 'subtracting', 'subtraction']:
        mathSubtraction()
    elif operationChoice in ['multiply', '*', 'x', 'multipying', 'multiplication']:
        mathMultiplication()
    elif operationChoice in ['divide', '/', 'dividing', 'division']:
        mathDivision()
    else:
        print("Sorry, That Was an Invalid Choice")

Python3: If elif else with while loops in a function

3 Answers3