Comments on Chad W. L. Whitacre: A use for the carriage return

I discovered this when I was developing my first b...

2009-04-08T23:57:00.000-04:00

I discovered this when I was developing my first bootloader. Whenever I printed text and ended it with a newline, it would skip to the next line at the same column:

Welcome to the YakOS bootloader!
Now loading stage 2....

I think having \r\n as the EOL indicator was an easy way to print a file correctly to stdout.

I was trying to figure out how to make a countdown...

2009-01-08T09:51:00.000-05:00

I was trying to figure out how to make a countdown clock, and this totally helped me out. Thanks!

import sys
import time

flush = sys.stdout.flush
sleep = time.sleep

print 'How much time do you want on the clock?',
answer = raw_input()
answer = answer.split(':')

hrs = int(answer[0])
mns = int(answer[1])
sec = int(answer[2])

pause = 1

while sec >= 0:
print '\r%02i:%02i:%02i' % (hrs, mns, sec),
flush()
sleep(pause)
sec -= 1
if sec == 0:
if mns > 0:
mns -= 1
sec += 59
elif mns == 0 and hrs > 0:
hrs -= 1
mns += 59
sec += 59

Oooh, neat! And extra points for 3.0 syntax, Anony...

2008-11-25T18:56:00.000-05:00

Oooh, neat! And extra points for 3.0 syntax, Anonymous. ;^)

Try:print('\rvery long status', end='')print('\rsh...

2008-11-25T18:24:00.000-05:00

Try:

print('\rvery long status', end='')
print('\rshort status', end='')

To solve this use:

print('\rvery long status', end='')
print('\r\x1b[K\rshort status', end='')

More at: http://www.termsys.demon.co.uk/vtansi.htm

Every once in a while, along comes a post that rem...

2008-11-25T01:49:00.000-05:00

Every once in a while, along comes a post that reminds me of just how much baggage I still have sloshing around in my head.

Here is a 'spinner'

bash$ python -c '
> import time,sys
> while True:
> ..for char in r"/-\|":
> ....sys.stdout.write("\r" + char)
> ....sys.stdout.flush()
> ....time.sleep(0.1)
> '

(dots for indentation)

Here's an animated example showing write and flush...

2008-11-25T00:46:00.000-05:00

Here's an animated example showing write and flush.

import sys
import time

sleep = time.sleep
write = sys.stdout.write
flush = sys.stdout.flush

message = 'PYTHON'
for i, c in enumerate(message):
    write('_' * i + c)
    flush()
    sleep(.5)
    write('\r')

write(message)
flush()
sleep(.5)
write('!')
flush()
sleep(.5)

While '\r' returns to the beginning of the line, it doesn't clear what's already on the line so you may need to pad your text with trailing spaces to cover the previous text.

Gabriel: what she said.However I'm not seeing the ...

2008-11-24T18:57:00.000-05:00

Gabriel: what she said.

However I'm not seeing the comma suppress the newline:

>>> print 'foo',
foo
>>> import sys
>>> sys.stdout.write('foo')
foo>>>

That'd be a neat trick if it worked.

@Anonymous: Thanks a lot :)sooooooooo nice this wa...

2008-11-24T17:36:00.000-05:00

@Anonymous: Thanks a lot :)
sooooooooo nice this way :D

@Gabrielprint is putting a '\n' at the end.you can...

2008-11-24T17:24:00.000-05:00

@Gabriel
print is putting a '\n' at the end.

you can either use

print '\r'+str(i),
# the comma prevent the newline

or
sys.stdout.write('\r'+str(i))

in either case you need to call
sys.stdout.flush() to flush the lines when there isn't a newline at the end.

#!/usr/bin/env pythonimport timefor i in range(100...

2008-11-24T17:05:00.000-05:00

#!/usr/bin/env python
import time

for i in range(100):
____time.sleep(.01)
____print '\r'+i*'='+'>'

indentation with '_' sorry.

I tried to use that some time ago, but did not man...

2008-11-24T17:04:00.000-05:00

I tried to use that some time ago, but did not manage to print without '\n' so this does'nt work

#!/usr/bin/env python
import time

for i in range(100):
time.sleep(.01)
print '\r'+i*'='+'>'

any idea?

Thats awesome. I always wondered how that worked.....

2008-11-24T16:10:00.000-05:00

Thats awesome. I always wondered how that worked...

You and rapid research; Don't you have a job? ;^) ...

2008-11-24T16:08:00.000-05:00

You and rapid research; Don't you have a job? ;^) Again, thanks for the help.