Newbie Loop Question (Python)

[Spectre557]

Hey,

After a long break I'm having another foray into the world of programming in Python, and I'm really stuck with something. Loops. I think.

I think I need to use a loop for the desired effect, but I'm not sure. Basically what I want to do is this:
- Ask the user a question, expecting a yes or no input
- If they say yes, do one thing
- If they say no, do another thing
- If they input anything other than yes or no, repeat the question.

I want to loop in the sense that I want it to keep repeating the question until a sufficient answer is given. But having looked at several tutorials and online sources, I can't get my head around how to use a loop for anything more than a very basic "keep doing x until y is z", typically like this:

Code: Select all

x = 1
while x < 10:
   print "blah"
   x = x + 1
print "blahblahblah"

The problem is I don't want it to just keep doing something, I want it to actually return to an earlier point in the code, and continue from there, not do the same thing over and over. Or am I looking at this the wrong way?

Someone please enlighten me!

[aNewHobby4me]

Try using this as an example.

Its similar to what you are describing, maybe enough to help.

[edited link]

[Defience]

It's kind of like the question you had posted before about the "if/elif/else" usage. You can use a simple 'While' loop like this:

Code: Select all

while True:
    response = raw_input("Are you an elite hacker?  ")
    if response.lower() == "yes":
         print "Can you hack a myspace for me then?!"
         break
    elif response.lower() == "no":
        print "Poser! Do you know anyone that is?"
        break
    else:
        print "Please enter a yes or no or I will keep asking the same question!"


[Spectre557]

It's kind of like the question you had posted before about the "if/elif/else" usage. You can use a simple 'While' loop like this:

Code: Select all

while True:
    response = raw_input("Are you an elite hacker?  ")
    if response.lower() == "yes":
         print "Can you hack a myspace for me then?!"
         break
    elif response.lower() == "no":
        print "Poser! Do you know anyone that is?"
        break
    else:
        print "Please enter a yes or no or I will keep asking the same question!"


Ahhh, that would appear to be exactly what I was looking for. Thanks mate!

[Defience]

No problem. Glad I could help

[Spectre557]

Hmm, I've had a go with this, and I think I understand it pretty well now, but I've encountered another problem with the while loop.

What I want to do is print a series of lines of text on screen over and over until input is given. My only problem is, how would I maintain a raw_input throughout the loop?

Or in other words, I want a loop with raw_input as a break.

Does that make any sense?

[insomaniacal]

I don't think you'll be able to use raw_input for that, because as soon as the script reaches "raw_input" in the code, it will stop executing the loop and wait for you to input something.

[Spectre557]

I don't think you'll be able to use raw_input for that, because as soon as the script reaches "raw_input" in the code, it will stop executing the loop and wait for you to input something.

That makes sense...

So do you know what I could use instead?

[insomaniacal]

I'm not an expert as far as programming goes, but I don't think you could do this in Python.

Maybe if you somehow wrote the script so that any button you press counts as a keyboard interrupt, but I have no clue if that is possible to do, and if it is, I've no idea on how to do that.

[Defience]

Ctrl -c will get the process to stop running, but I'm not sure I'm following what it is you're looking for. Did you want output something like this example:

>>>Enter yes or no:yes
Good choice
>>>Enter yes or no:no
Bad choice
>>>Enter yes or no:maybe
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:
>>>Enter yes or no:

so that the question will keep running until a yes or no is entered? If so, I don't see how that can be done because it's not going to accept new input until it stops running. Or am I misunderstanding you?