Horribly noobful string question

[SeNTry]

Hi Everyone,

My first post here as I just begin to learn programming in general and
python in particular. I have all the noobie confused questions, but as I
work thru the tutorials I'm sure I'll find most my answers.

This one is eluding me tho... I am working in the tutorials, writing scripts
as presented and then modifying and expanding on my own to try to learn.
I'm working with one that asks the user to 'guess a number I'm thinking',
and with simple while loop, flow control and operands, returning an answer
to guess again or you got it. I've added a 'playagain' function I've got
working, but what I want is to stop the program from crashing when someone
enters a string value instead of a int value. I know strings are immutable,
and they can be changed to an int equivalent, but I just want the script to
recognize the input as a string and print a simple "that's not a number, try
again' type of message. I can't find the syntax to include in the
if/elif/else block to include a line that says something like,

elif guess == <string>
print "that's not a number! please guess again!"

I know that's not right, but can you see what I'm looking for and offer a
suggestion?

Thanks in advance all.

[Fredrik Lundh]

Re: Horribly noobful string question

"SeNTry" wrote:
[color=blue]
> My first post here as I just begin to learn programming in general and
> python in particular. I have all the noobie confused questions, but as I
> work thru the tutorials I'm sure I'll find most my answers.
>
> This one is eluding me tho... I am working in the tutorials, writing scripts
> as presented and then modifying and expanding on my own to try to learn.
> I'm working with one that asks the user to 'guess a number I'm thinking',
> and with simple while loop, flow control and operands, returning an answer
> to guess again or you got it. I've added a 'playagain' function I've got
> working, but what I want is to stop the program from crashing when someone
> enters a string value instead of a int value. I know strings are immutable,
> and they can be changed to an int equivalent, but I just want the script to
> recognize the input as a string and print a simple "that's not a number, try
> again' type of message. I can't find the syntax to include in the
> if/elif/else block to include a line that says something like,[/color]

assuming you're using raw_input() to get the guess, you always
have a string (in python's sense of that word).

what you seem to want is to check if the string contains a number
or not. here's one way to do this:

guess = raw_input("make a guess: ")
if guess == secret:
print "congratulation s!"
elif not guess.isdigit() :
print "that's not a number! please guess again!"
...

isdigit returns true if the string contains nothing but digits:
[color=blue][color=green][color=darkred]
>>> help(str.isdigi t)[/color][/color][/color]

isdigit(...)
S.isdigit() -> bool

Return True if there are only digit characters in S,
False otherwise.

if you're using some other way to read user input, let us know.

</F>

[Xavier Morel]

Re: Horribly noobful string question

Fredrik Lundh wrote:[color=blue]
> "SeNTry" wrote:
>[color=green]
>> My first post here as I just begin to learn programming in general and
>> python in particular. I have all the noobie confused questions, but as I
>> work thru the tutorials I'm sure I'll find most my answers.
>>
>> This one is eluding me tho... I am working in the tutorials, writing scripts
>> as presented and then modifying and expanding on my own to try to learn.
>> I'm working with one that asks the user to 'guess a number I'm thinking',
>> and with simple while loop, flow control and operands, returning an answer
>> to guess again or you got it. I've added a 'playagain' function I've got
>> working, but what I want is to stop the program from crashing when someone
>> enters a string value instead of a int value. I know strings are immutable,
>> and they can be changed to an int equivalent, but I just want the script to
>> recognize the input as a string and print a simple "that's not a number, try
>> again' type of message. I can't find the syntax to include in the
>> if/elif/else block to include a line that says something like,[/color]
>
> assuming you're using raw_input() to get the guess, you always
> have a string (in python's sense of that word).
>
> what you seem to want is to check if the string contains a number
> or not. here's one way to do this:
>
> guess = raw_input("make a guess: ")
> if guess == secret:
> print "congratulation s!"
> elif not guess.isdigit() :
> print "that's not a number! please guess again!"
> ...
>[/color]

that, or just write something like

guess = raw_input("Make your guess > ")
try:
if int(guess) == secret:
# ok
except ValueError:
# no good

[SeNTry]

Re: Horribly noobful string question


"Xavier Morel" <xavier.morel@m asklinn.net> wrote in message
news:dnn2g8$l12 $1@aphrodite.gr ec.isp.9tel.net ...[color=blue]
> Fredrik Lundh wrote:[color=green]
>> "SeNTry" wrote:
>>[color=darkred]
>>> My first post here as I just begin to learn programming in general and
>>> python in particular. I have all the noobie confused questions, but as
>>> I
>>> work thru the tutorials I'm sure I'll find most my answers.
>>>
>>> This one is eluding me tho... I am working in the tutorials, writing
>>> scripts
>>> as presented and then modifying and expanding on my own to try to learn.
>>> I'm working with one that asks the user to 'guess a number I'm
>>> thinking',
>>> and with simple while loop, flow control and operands, returning an
>>> answer
>>> to guess again or you got it. I've added a 'playagain' function I've
>>> got
>>> working, but what I want is to stop the program from crashing when
>>> someone
>>> enters a string value instead of a int value. I know strings are
>>> immutable,
>>> and they can be changed to an int equivalent, but I just want the script
>>> to
>>> recognize the input as a string and print a simple "that's not a number,
>>> try
>>> again' type of message. I can't find the syntax to include in the
>>> if/elif/else block to include a line that says something like,[/color]
>>
>> assuming you're using raw_input() to get the guess, you always
>> have a string (in python's sense of that word).
>>
>> what you seem to want is to check if the string contains a number
>> or not. here's one way to do this:
>>
>> guess = raw_input("make a guess: ")
>> if guess == secret:
>> print "congratulation s!"
>> elif not guess.isdigit() :
>> print "that's not a number! please guess again!"
>> ...
>>[/color]
>
> that, or just write something like
>
> guess = raw_input("Make your guess > ")
> try:
> if int(guess) == secret:
> # ok
> except ValueError:
> # no good[/color]
[color=blue][color=green]
>>
>> assuming you're using raw_input() to get the guess, you always
>> have a string (in python's sense of that word).
>>
>> what you seem to want is to check if the string contains a number
>> or not. here's one way to do this:
>>
>> guess = raw_input("make a guess: ")
>> if guess == secret:
>> print "congratulation s!"
>> elif not guess.isdigit() :
>> print "that's not a number! please guess again!"
>> ...
>>[/color]
>
> that, or just write something like
>
> guess = raw_input("Make your guess > ")
> try:
> if int(guess) == secret:
> # ok
> except ValueError:
> # no good[/color]

Sry for late reply, I've been out of town. Thanks for the responses, I'm
just sitting down to try these out. I'm kind of surprised there's not a
more obvious way to handle simply identifying strings.

Anyways, here's the original code snippet from a tut. and then my modified
effort. I was using input instead of raw_input. Looking at it now I'm not
even sure why I did some of the stuff I did HAHA! I just made functions for
convenience and practice. I'm sure it's laughable, but maybe you can see
what I was doing and tell me what other errors I made just for learning...

Everything seems to work well, except when the playagain function in my
modified code gets a '2' input to quit, it prints 'aw, ok bye then' and then
the next line is the print from the loopfunc if statement, "looping while
statement now complete". If I remove the again="" line in the playagain
function, it prints 2 times... wierd. I put this in there because I
suspected that the variable was remaining and wanted to clear it at the
start of the function, but I've now read that the variable in a function is
destroyed when the function ends... is this right? My brain hurts...

ORIGINAL
number = 24
guess = int(raw_input(' Enter an integer : '))

if guess == number:
print 'Congratulation s, you guessed it.' # New block starts here
print "(but you do not win any prizes!)" # New block ends here
elif guess < number:
print 'No, it is a little higher than that' # Another block
# You can do whatever you want in a block ...
else:
print 'No, it is a little lower than that'
# you must have guess > number to reach here

print 'Done'
# This last statement is always executed, after the if statement is
executed**MODIF IED**#define two functions first, then use them.def
loopfunc(loopin g): while looping: guess= input("guess a number.
see if you can guess what I'm thinking") if guess == number:
print "you got it!" looping=False playagain("")
print "looping while statement now complete" #for clarification when running
elif guess < number: print "nope, a little higher!" else:
print "no, a little lower!"def playagain(again ): again="" #removing
this line make the 'looping while..' statement print 2 times again=
input("would you like to play again? type '1' for yes and '2' for no") if
again==1: print "great!" loopfunc(True) elif again==2:
print "aww! Ok, bye then" return else: print "that's not a
1 or a 2! Try again!" playagain("")nu mber=24loopfunc (True)

[SeNTry]

Re: Horribly noobful string question

SRY, that last bit of code got messed up. Hopefully it will look right
now...

#define two functions first, then use them.

def loopfunc(loopin g):
while looping:
guess= input("guess a number. see if you can guess what I'm thinking")
if guess == number:
print "you got it!"
looping=False
playagain("")
print "looping while statement now complete"
elif guess < number:
print "nope, a little higher!"
else:
print "no, a little lower!"

def playagain(again ):
again=""
again= input("would you like to play again? type '1' for yes and '2' for
no")
if again==1:
print "great!"
loopfunc(True)
elif again==2:
print "aww! Ok, bye then"
return
else:
print "that's not a 1 or a 2! Try again!"
playagain("")
number=24
loopfunc(True)
[color=blue]
>
>[/color]