Simple ways to break a *while* with a function

Question

I usually run into this problem:

while True:

  input_chute = int(input("chute: "))

  if input_chute == 0: break

bla bla bla ...

In that example above I break while with a condition and a break, however, when I create a function:

def jogo():
  input_chute = int(input("chute: "))

  if input_chute == 0: break

while True:

  jogo()

bla bla bla ...

I need to use global and a variable just to function as an accountant or I have to leave if input_chute == 0: break out of function.

Is there any easier (or just different) way to do this?

BS: I’m still junior, I don’t know much.

Answer 1

I don’t understand why you don’t want to do the break in the while. That’s where he belongs, there’s no point in leaving him in another role.

What you can do is model the code a little differently. Something like:

def fazer_jogada():
  return int(input("chute: "))

def jogo():
  jogada = fazer_jogada()
  while jogada != 0:
    # lógica do jogo
    jogada = fazer_jogada()

jogo()

^{See working on Repl.it}

Answer 2

It doesn’t seem like a good idea. It seems that the while is part of the function algorithm (it is one that asks for a data validating it) and should not be separated. Even the name of the function is not good and so already indicates that there is something wrong there.

If the noose were part of the game as a whole there would be enough to do, but it does not have the break. The validation function does not come out until something valid is typed, the loop is purposefully infinite. Of course, there is an output, but then as it is a function, it is not of the loop that you want to leave, it is of the function. The break works too, because there is a return implicit at the end of every function, and if there is nothing after the loop block, it is it that will run, but I find it simpler to be explicit in the output.

def pedeChute():
    while True:
        try:
            chute = int(input("chute: "))
            if chute == 0:
                return chute
        except:
            pass

def jogo():
    while True:
        #algo aqui
        chute = pedeChute() #sempre será válido
        #algo aqui

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

If it makes sense to have the comparison outside the function (it doesn’t look but it can be), then it would only be a way out of the game loop and not a validation, then it could do so:

def pedeChute():
    while True:
        try:
            chute = int(input("chute: "))
            return chute
        except:
            pass

def jogo():
    while True:
        #algo aqui
        chute = pedeChute() #sempre será válido
        if chute == 0:
            break
        #algo aqui

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

Note that in the function that asks for the data does not make a complete validation, only analyzes if a number has been typed.

This is a typical junior mistake (or train) and at least at this point gives an indication that wants to reach full (some people do not want, they will be stubborn and will not ask, make mistakes all their lives, and so will not evolve). It is not a mistake of code, but of definition of responsibility, a junior misses this, a full can no longer, so there are many people with this title but not ability to do so. Learning this already helps to move to the next level, but understanding that when you do not know if you ask and listen to who already has the experience is what makes evolve the most.