Do while loop in Python 3

Question

I wanted to have some sort of thing that if the user inputs "Quit", the program breaks. I think that I could achieve that with a do while loop but I don't understand how to implement it. Please help me.

num1 = float(input("Enter First Number: "))
num2 = float(input("Enter second number: "))
op = input("Enter Operator: ")

if op == "*":
    print(num1 * num2)

elif op == "+":
    print(num1 + num2)

elif op == "-":
    print(num1 - num2)

elif op == "/":
    print(num1 / num2)

elif op == "%":
    print(num1 % num2)

else:
    print("Invalid Operator")

Welcome to StackOverflow! I see you're a new contributor, so I advise you to check out How to ask a good question, How to create a minimal reproducible example, and Why is "Can someone help me?" not an actual question?. — Brian61354270
– Brian61354270, Commented Apr 4, 2021 at 15:39
stackoverflow.com/questions/23294658/… this might give you some kind of orientation — dot.Py
– dot.Py, Commented Apr 4, 2021 at 15:42

dot.Py · Accepted Answer · 2021-04-04 15:46:30Z

1

while True:
    try:
        #insert your "loop" here
        [.....]
        
    except ValueError:
        #restart the loop
        continue

    else:
        #exit the loop
        break

answered Apr 4, 2021 at 15:46

dot.Py

5,1775 gold badges35 silver badges55 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

will-hedges · Accepted Answer · 2021-04-04 15:49:33Z

0

while True:
    while True:
        num1 = input("Enter First Number: ")
        if num1.lower() == "quit":
            quit()
        try:
            num1 = int(num1)
            break
        except ValueError:
            print(f"{num1} is not an integer.")

    while True:
        num2 = input("Enter second number: ")
        if num2.lower() == "quit":
            quit()
        try:
            num2 = int(num2)
            break
        except ValueError:
            print(f"{num2} is not an integer.")

    op = input("Enter Operator: ")
    if op.lower() == "quit":
        quit()

    if op == "*":
        print(num1 * num2)
    elif op == "+":
        print(num1 + num2)
    elif op == "-":
        print(num1 - num2)
    elif op == "/":
        print(num1 / num2)
    elif op == "%":
        print(num1 % num2)
    else:
        print("Invalid Operator")

answered Apr 4, 2021 at 15:49

will-hedges

1,2941 gold badge12 silver badges22 bronze badges

2 Comments

Brain Gym Over a year ago

explanation please? I don't understand do while loops.

will-hedges Over a year ago

@BrainGym a while loop runs while a condition is met. In this case, while True: is effectively an infinite loop (while True will always be True). What I've done is have each step run until the input is valid, or until the user enters "quit." break will break the program out of the infinite loop. So this program runs each step until it receives a valid input or the user enters "quit." I recommend reading ATBSWP Chapter 2 for a more thorough explanation.

Collectives™ on Stack Overflow

Do while loop in Python 3

2 Answers 2

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related