where the extra space comes from on the stdout

[alf]

Hi,

I can not find out where the extra space comes from. Run following:

import os,sys
while 1:
print 'Question [Y/[N]]?',
if sys.stdin.readl ine().strip() in ('Y','y'):
#do something
pass

$ python q.py
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?n
Question [Y/[N]]?
Question [Y/[N]]?


There is a space evrywhere just before Q

Any insight?

--
alfz1

[Steve Holden]

Re: where the extra space comes from on the stdout

alf wrote:

Hi,
>
I can not find out where the extra space comes from. Run following:
>
import os,sys
while 1:
print 'Question [Y/[N]]?',
if sys.stdin.readl ine().strip() in ('Y','y'):
#do something
pass
>
$ python q.py
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?n
Question [Y/[N]]?
Question [Y/[N]]?
>
>
There is a space evrywhere just before Q
>
Any insight?
>

Yup. When you execute a print statement with a comma at the end it
doesn't output the space, it simply sets a flag reminding it that there
should be a space before the next item on the same line. If the next
character out is a newline then the space flag is reset, but in this
case the newline was provided by the input, so you get a space at the
start of the next output.

regards
Steve
--
Steve Holden +44 150 684 7255 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://holdenweb.blogspot.com
Recent Ramblings http://del.icio.us/steve.holden

[Gabriel G]

Re: where the extra space comes from on the stdout

At Saturday 30/9/2006 19:09, Steve Holden wrote:

while 1:
print 'Question [Y/[N]]?',
if sys.stdin.readl ine().strip() in ('Y','y'):
#do something
pass

$ python q.py
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y

>Yup. When you execute a print statement with a comma at the end it
>doesn't output the space, it simply sets a flag reminding it that there
>should be a space before the next item on the same line. If the next
>character out is a newline then the space flag is reset, but in this
>case the newline was provided by the input, so you get a space at the
>start of the next output.

You could try using
print '\rQuestion?',


Gabriel Genellina
Softlab SRL





_______________ _______________ _______________ _____
Preguntá. Respondé. Descubrí.
Todo lo que querías saber, y lo que ni imaginabas,
está en Yahoo! Respuestas (Beta).
¡Probalo ya!

http://www.yahoo.com.ar/respuestas

[Simon Percivall]

Re: where the extra space comes from on the stdout


alf wrote:

Hi,
>
I can not find out where the extra space comes from. Run following:
>
import os,sys
while 1:
print 'Question [Y/[N]]?',
if sys.stdin.readl ine().strip() in ('Y','y'):
#do something
pass
>
$ python q.py
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?y
Question [Y/[N]]?n
Question [Y/[N]]?
Question [Y/[N]]?
>
>
There is a space evrywhere just before Q
>
Any insight?

You already got the answer, but as for the rest: It's really easier for
you if you use raw_input() for your question/input pair instead.

[alf]

Re: where the extra space comes from on the stdout

Simon Percivall wrote:

>
You already got the answer, but as for the rest: It's really easier for
you if you use raw_input() for your question/input pair instead.
>

thx, this is what I was looking for, alf