good ways to convert string into time

[Hank]

hi,

i have a string as follows

18Nov2003:18:23 :43:405

Is there an easy way to convert that to absolute time? What i really
want to do is to parse these times from a log file and do time
comparisons, averages, stop minus start (elapsed).

Probably create my own conversion table i guess?

thanks

[Peter Hansen]

Re: good ways to convert string into time

Hank wrote:[color=blue]
>
> i have a string as follows
>
> 18Nov2003:18:23 :43:405[/color]

It's a minor point, but what happens for days-of-the-month that are
less than 10? Leading zero, or one character shorter? Same question
goes for the other fields, I suppose...
[color=blue]
> Is there an easy way to convert that to absolute time? What i really
> want to do is to parse these times from a log file and do time
> comparisons, averages, stop minus start (elapsed).
>
> Probably create my own conversion table i guess?[/color]

Probably not, actually...

-Peter

[Sac]

Re: good ways to convert string into time

Hank wrote:
[color=blue]
> hi,
>
> i have a string as follows
>
> 18Nov2003:18:23 :43:405
>
> Is there an easy way to convert that to absolute time? What i really
> want to do is to parse these times from a log file and do time
> comparisons, averages, stop minus start (elapsed).
>
> Probably create my own conversion table i guess?
>
> thanks[/color]


Hank,

A source that may be of interest to you is "Text Processing in Python"
by Dr. David Mertz.

Excellent reference.

[Jp Calderone]

Re: good ways to convert string into time

On Tue, Nov 18, 2003 at 09:58:08AM -0800, Hank wrote:[color=blue]
> hi,
>
> i have a string as follows
>
> 18Nov2003:18:23 :43:405
>
> Is there an easy way to convert that to absolute time? What i really
> want to do is to parse these times from a log file and do time
> comparisons, averages, stop minus start (elapsed).
>
> Probably create my own conversion table i guess?[/color]

time.strptime

http://www.python.org/doc/lib/module-time.html

[color=blue]
>
> thanks
> --
> http://mail.python.org/mailman/listinfo/python-list
>[/color]

[Gerrit Holl]

Re: good ways to convert string into time

<quote name="Hank" date="106914588 8" email="soundwav e56@yahoo.ca">[color=blue]
> i have a string as follows
>
> 18Nov2003:18:23 :43:405[/color]
[color=blue]
> Is there an easy way to convert that to absolute time? What i really
> want to do is to parse these times from a log file and do time
> comparisons, averages, stop minus start (elapsed).
>
> Probably create my own conversion table i guess?[/color]
</quote>

You can use time.strptime:
strptime(string , format) -> struct_time

Parse a string to a time tuple according to a format specification.
See the library reference manual for formatting codes (same as strftime()).

Gerrit.

--
Mozilla _is_ the web: it grows faster than you can download it.
1011001 1101111 1110101 1110010 1110011 0101100
1000111 1100101 1110010 1110010 1101001 1110100

[Bengt Richter]

Re: good ways to convert string into time

On 18 Nov 2003 09:58:08 -0800, soundwave56@yah oo.ca (Hank) wrote:
[color=blue]
>hi,
>
>i have a string as follows
>
>18Nov2003:18:2 3:43:405
>
>Is there an easy way to convert that to absolute time? What i really
>want to do is to parse these times from a log file and do time
>comparisons, averages, stop minus start (elapsed).
>
>Probably create my own conversion table i guess?
>
>thanks[/color]

Quick and dirty using the time module (and re to split your string)
Not tested beyond what your see here!

====< s2t.py >============== ====
import time,re
rxo = re.compile(r'(\ d+)([a-zA-Z]+)(\d+):(\d+):( \d+):(\d+):(\d+ )')
monthnums = dict([(mo,i+1) for i,mo in enumerate(
'Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec'.split())])
def s2t(s, dst=-1): # guess daylight svgs
da,mo,yr,hr,min ,sec,ms = rxo.search(s).g roups()
mo = monthnums[mo]
tinfo = map(int, (yr,mo,da,hr,mi n,sec,ms))
ms = tinfo.pop()
return time.mktime(tin fo+[0,0,dst])+ms/1000.0
=============== =============== ==
[color=blue][color=green][color=darkred]
>>> import s2t
>>> s2t.s2t('18Nov2 003:18:23:43:40 5')[/color][/color][/color]
1069208623.405[color=blue][color=green][color=darkred]
>>> import time
>>> time.ctime(s2t. s2t('18Nov2003: 18:23:43:405'))[/color][/color][/color]
'Tue Nov 18 18:23:43 2003'

IOW, s2t converts your time info to a floating point number in seconds from the epoch,
which e.g., time.ctime and other time functions can use.

The milliseconds (I assumed) are ignored by ctime, but I tacked them on in the number returned.
(Note that floating point won't represent all decimals accurately, but it should be good rounded
to ms, e.g.,
[color=blue][color=green][color=darkred]
>>> from ut.exactdec import ED
>>> ED(s2t.s2t('18N ov2003:18:23:43 :405'),'all')[/color][/color][/color]
ED('1069208623. 404999971389770 5078125')

That's all the bit info. Looks like a good four 9's below your ms unit.
[color=blue][color=green][color=darkred]
>>> ED(s2t.s2t('18N ov2003:18:23:43 :405'),'all').r ound(3)[/color][/color][/color]
ED('1069208623. 405')


PS. I think there is a bug in time.mktime -- I accidentally got it trying to find time zero:
[color=blue][color=green][color=darkred]
>>> s2t.s2t('01Jan1 970:00:00:00:00 0', 1)[/color][/color][/color]
25200.0[color=blue][color=green][color=darkred]
>>> s2t.s2t('31Dec1 969:23:00:00:00 0', 1)[/color][/color][/color]
21600.0[color=blue][color=green][color=darkred]
>>> s2t.s2t('31Dec1 969:17:00:00:00 0', 1)[/color][/color][/color]
0.0[color=blue][color=green][color=darkred]
>>> s2t.s2t('31Dec1 969:17:00:00:00 0', 0)[/color][/color][/color]
3600.0[color=blue][color=green][color=darkred]
>>> s2t.s2t('31Dec1 969:17:00:00:00 0', 1)[/color][/color][/color]
0.0[color=blue][color=green][color=darkred]
>>> s2t.s2t('31Dec1 969:16:00:00:00 0', 1)[/color][/color][/color]
(boom)

I got:

The instruction at "0x7802a7ff " referenced memory at "0x00000000 ". The memory
could not be "read".

That shouldn't happen no matter what garbage I type as args, ISTM ;-/
Guess I'll post a plainer mktime example separately.

Regards,
Bengt Richter