Flowchart getting complicated with while loops in Python-CodePudding

I would appreciate some help with this:

I try to make a form-program of the "Then why worry" philosophy:

I wrote this code, but I can't understand how do I make the while loop repeat itself every time the user doesn't enter "yes" or "no" in both questions.

problem = str(input("Do you have a problem in life? "))
problem = problem.replace(" ", "").lower() #nevermind caps or spaces
while problem:
  if problem not in ("yes","no"):
   print("Please enter YES or NO")
  if problem == "no":
    break
  if problem == "yes": 
   something = str(input("Do you have something to do about it? "))
  something = something.replace(" ","").lower()
  while something:
    if something not in ("yes","no"):
      print("Please enter YES or NO")
    elif: 
     break
print("Then why worry?")

CodePudding user response：

I'd suggest to use while True loops, so you can put the input code once, then with the correct condition and break you're ok

while True:
    problem = input("Do you have a problem in life? ").lower().strip()

    if problem not in ("yes", "no"):
        print("Please enter YES or NO")
        continue

    if problem == "no":
        break

    while True:
        something = input("Do you have something to do about it? ").lower().strip()
        if something not in ("yes", "no"):
            print("Please enter YES or NO")
            continue
        break
    break

print("Then why worry?")

Using walrus operator (py>=3.8) that could be done easier

while (problem := input("Do you have a problem in life? ").lower().strip()) not in ("yes", "no"):
    pass
if problem == "yes":
    while (something := input("Do you have something to do about it? ").lower().strip()) not in ("yes", "no"):
        pass

print("Then why worry?")

CodePudding user response：

Your algorithm is linear, there is no loops in there. So, the only place you need a loop is when you try to get correct response from the user. So, I'd propose you to move that into a function and then your example turns into this:

def get_user_input(prompt):
    while True:
        reply = input(prompt).replace(" ", "").lower()
        if reply in ['yes', 'no']:
            return reply
        print("Please enter YES or NO")

problem_exists = get_user_input("Do you have a problem in life? ")
if problem_exists == 'yes':
    action_possible = get_user_input("Do you have something to do about it? ")
print("Then why worry?")