"spir" <denis.s...@free.fr> wrote in message
news:20090228081629.36a24...@o...
Le Sat, 28 Feb 2009 06:34:07 +0200,
George Wahid <geoter...@gmail.com> s'exprima ainsi:
I downloaded python 3.0.1 today and started experimenting with the new
print statement.
>>>import time
>>>for l in 'the answer':
... print(l,end='')
... time.sleep(0.1)
the code is supposed to print "the answer" with a 0.1 second long
pause between the letters. instead, it waits for 1 second (
0.1*len("the answer") seconds ) and then prints "the answer". what am
I doing wrong ?
Indeed, it does the same for me with python 2.5:
from time import sleep
for c in "1234567890":
sleep(0.25)
print c,
I guess python underlying outputs are managed like a queue that is flushed
at certain points, eg whan a newline comes.
Already noticed weird outputs messing up ordinary prints (~ sys.stdout)
and exceptions messages (sys.stderr). I'd like to know more about that.
both replacing print(l,end='') with print(l) or using the msvcrt
module instead of the print function work fine.
The same with py2.5. Without the ',', all is fine. Maybe there is a trick
to force python printing ot in due time, but I have no idea, sorry.
stdout is line-buffered. Here's the trick:
import time
import sys
for l in 'the answer':
print(l,end='')
sys.stdout.flush()
time.sleep(0.1)
-Mark
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