Problem I have with a while loop/boolean/or

[israphelr]

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

[Paul Rubin]

"is*******@googlemail.com" <is*******@googlemail.comwrites:

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

Suppose your hint is 'y'. Ask yourself these two questions:

1. Is (hint != 'n') true?
2. Is (hint != 'y') true?

Now ask yourself what the condition in your while loop says.

[Larry Bates]

is*******@googlemail.com wrote:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

Your if test is wrong.

If hint='n'

hint !='n' is False
hint !='y' is True

False or True equals True

I think you want something like:

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while hint not in ['y', 'n']:
hint = raw_input("Please specify a valid choice: ")

-Larry

[israphelr]

On Mar 13, 10:43 pm, Paul Rubin <http://[e-mail]:

"[e-mail]" <[e-mail]:

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

Suppose your hint is 'y'. Ask yourself these two questions:

1. Is (hint != 'n') true?
2. Is (hint != 'y') true?

Now ask yourself what the condition in your while loop says.

Thanks.

*puts my head under a white sheet* =/

[israphelr]

On Mar 13, 10:50 pm, Larry Bates <[e-mail]:

[e-mail] wrote:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

Your if test is wrong.

If hint='n'

hint !='n' is False
hint !='y' is True

False or True equals True

I think you want something like:

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while hint not in ['y', 'n']:
hint = raw_input("Please specify a valid choice: ")

-Larry

Thanks Larry.

[John McMonagle]

is*******@googlemail.com wrote:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

Try it a different way:

while True:
hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()
if hint != 'y' and hint != 'n':
print "Please answer y or n"
continue
else:
break
if hint == 'y':
do_your_hint_stuff()

>

[Bart Willems]

John McMonagle wrote:

Try it a different way:

while True:
hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()
if hint != 'y' and hint != 'n':
print "Please answer y or n"
continue
else:
break
if hint == 'y':
do_your_hint_stuff()

I always try to stay away from 'negative' operators if possible, to
improve readability:

while True:
hint = raw_input('\nAre you stuck? y/n: ').lower()
if hint = 'y' or hint = 'n':
break
else:
print 'Please answer yes or no'

[hg]

is*******@googlemail.com wrote:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

Hi,

Whatever hint is:
(hint != 'n') or (hint != 'y')
is always going to be true

as it cannot really be both at the same time

use "and" instead of "or"

hg

[hg]

hg wrote:

is*******@googlemail.com wrote:

>Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

As for here when I enter n, I can leave the while loop.

Anyway I can't put my finger on this, so I'd be real grateful if
someone could tell me what I've done wrong. Thanks.
(I have a guy feeling it's something really silly I'm overlooking...)

Hi,

Whatever hint is:
(hint != 'n') or (hint != 'y')
is always going to be true

as it cannot really be both at the same time

use "and" instead of "or"

hg

oops, meant to answer to the main post

[Scott David Daniels]

Bart Willems wrote:

...
I always try to stay away from 'negative' operators if possible, to
improve readability:

while True:
hint = raw_input('\nAre you stuck? y/n: ').lower()
if hint = 'y' or hint = 'n':
break
else:
print 'Please answer yes or no'

And if you really want to see what is going wrong, replace that last by:
print 'Please answer yes or no (not %r):' % hint

--
--Scott David Daniels
sc***********@acm.org

[Steve Holden]

Scott David Daniels wrote:

Bart Willems wrote:

>...
I always try to stay away from 'negative' operators if possible, to
improve readability:

while True:
hint = raw_input('\nAre you stuck? y/n: ').lower()
if hint = 'y' or hint = 'n':
break
else:
print 'Please answer yes or no'

And if you really want to see what is going wrong, replace that last by:
print 'Please answer yes or no (not %r):' % hint

Better still, use

Please answer y or n

since those are the values you are testing for ...

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden
Blog of Note: http://holdenweb.blogspot.com
See you at PyCon? http://us.pycon.org/TX2007

[gslindstrom]

On Mar 13, 5:34 pm, "[e-mail]"
<[e-mail]:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

I'd even make it a little more bullet-proof by using lower()

while hint.lower() not in ('y','n'):
stuff

That way if the user types in 'Y' on 'N' it will still work. I've
even gone further on occasion

while hint.lower()[0] not in ('y','n'):
stuff

so if they type 'Yes' or 'No' you're still good.

--greg

[Fabio FZero]

On Mar 13, 7:34 pm, "[e-mail]"
<[e-mail]:

Hi all.

I have a problem with some code :(

-----------

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while (hint != 'n') or (hint != 'y'):
hint = raw_input("Please specify a valid choice: ")

---------------------------------------------

so everytime I run the program, and enter my choice as y or n, I'm
told to 'Please Specify a valid Choice Again' and can't get out of the
loop.

Why don't you try this instead:

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while not hint in 'yn':
hint = raw_input("Please specify a valid choice: ")

[]s
FZero

[Gabriel Genellina]

En Wed, 14 Mar 2007 15:34:20 -0300, Fabio FZero <fa*********@gmail.com>
escribió:

Why don't you try this instead:

hint = raw_input("\nAre you stuck? y/n: ")
hint = hint.lower()

while not hint in 'yn':
hint = raw_input("Please specify a valid choice: ")

Dangerous: what if the user types 'yn'?
`hint in list('yn')` may be better, if you don't like the previous answers.

--
Gabriel Genellina