delta time = time stop - time start

**Guilherme Salgado** · Jul 18 '05, 07:54 AM

Re: delta time = time stop - time start

On Mon, 2004-01-26 at 04:08, engsol wrote:
[...][color=blue]
> The routine I came up with is below, but seems a bit clunky.
> Is there a better way of doing this? I think it relies too much on integers rounding off in the proper direction, a la
> d_time_hr = d_time / 3600 below.
>[/color]

You can use mx.DateTime
(http://www.lemburg.com/files/python/mxDateTime.html).
Then, the code will look like this:

from mx import DateTime
start = DateTime.now()
# do something ...
stop = DateTime.now()
delta = (stop - start).strftime ("%H:%M:%S")

hope it helps.
[color=blue]
> Also, this will have to transition to Linux, if that makes a difference.
>
> START CODE:
>
> import string
>
> def deltatime(start , stop):
>
> t_start = (string.atoi(st art[0:2]) * 3600) + (string.atoi(st art[3:5]) * 60) + string.atoi(sta rt[6:8])
> t_stop = (string.atoi(st op [0:2]) * 3600) + (string.atoi(st op [3:5]) * 60) + string.atoi(sto p [6:8])
>
> if t_start < t_stop:
> d_time = t_stop - t_start
> else:
> d_time = (86400 - t_start) + t_stop
>
> d_time_hr = d_time / 3600
> d_time_min = (d_time - d_time_hr * 3600) / 60
> d_time_sec = (d_time - d_time_hr * 3600) - (d_time_min * 60)
>
> return str(d_time_hr) + 'hr ' + str(d_time_min) + 'min ' + str(d_time_sec) + 'sec'
>
> END CODE[/color]

[]'s
Salgado
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**Dan Bishop** · Jul 18 '05, 07:54 AM

Re: delta time = time stop - time start

engsol <engsolnorm@ipn s.com> wrote in message news:<cs9910pcg ktdrp1e8abctopt ue7braqvqu@4ax. com>...[color=blue]
> I'm using Python to parse a bunch of s/w test files and make csv files for later report generation by MS ACCESS....(my boss
> loves the quick turn-around compared to C). Each log file may contain one or more 'sessions', and each session may contain
> one or more 'nodes'.
>
> Each session in the log has an ASCII start and stop time, as does each node.
> I have the basic parse part done for parameters, errors, etc., but noticed my routine for determining how long each
> session/node took (delta time) was a bit repetitive, so decided to make a 'stand-alone' routine to handle this.
>
> The time format from the log is in the format of:
> hh:mm:ss
> and is a string with leading zeros where appropiate. Date is never a factor. The longest "delta" is maybe 5 hours.
>
> The routine I came up with is below, but seems a bit clunky.
> Is there a better way of doing this? I think it relies too much on integers rounding off in the proper direction, a la
> d_time_hr = d_time / 3600 below.[/color]

It also relies on -Qold. Please use the // operator for integer
division. Or you're going to regret it when you upgrade to Python
3.0.
[color=blue]
> Also, this will have to transition to Linux, if that makes a difference.[/color]

In your code, it makes no difference. I'm using a Linux box right
now.
[color=blue]
> START CODE:
>
> import string[/color]

Unless you have a very old version of Python, this is no longer
needed; string.atoi has been officially replaced with the "int"
constructor.
[color=blue]
> def deltatime(start , stop):
>
> t_start = (string.atoi(st art[0:2]) * 3600) + (string.atoi(st art[3:5]) * 60) + string.atoi(sta rt[6:8])
> t_stop = (string.atoi(st op [0:2]) * 3600) + (string.atoi(st op [3:5]) * 60) + string.atoi(sto p [6:8])[/color]

Rather than count character positions, take advantage of the fact that
the strings are colon-delimited.

def toSeconds(timeS tring):
hour, min, sec = map(int, timeString.spli t(':'))
return (hour * 60 + min) * 60 + sec

t_start = toSeconds(start )
t_stop = toSeconds(stop)
[color=blue]
> if t_start < t_stop:
> d_time = t_stop - t_start
> else:
> d_time = (86400 - t_start) + t_stop[/color]

You can eliminate the if-else test by taking advantage of Python's %
operator

d_time = (t_stop - t_start) % 86400
[color=blue]
> d_time_hr = d_time / 3600
> d_time_min = (d_time - d_time_hr * 3600) / 60
> d_time_sec = (d_time - d_time_hr * 3600) - (d_time_min * 60)[/color]

Rather than calculate remainders the hard way, use the % operator. Or
since you need both the quotient and remainder, use the divmod
function.

d_time_min, d_time_sec = divmod(d_time, 60)
d_time_hr, d_time_min = divmod(d_time_m in, 60)
[color=blue]
> return str(d_time_hr) + 'hr ' + str(d_time_min) + 'min ' + str(d_time_sec) + 'sec'[/color]

A more concise way of writing this is

return '%dhr %dmin %ssec' % (d_time_hr, d_time_min, d_time_sec)

The complete rewritten function is

def deltatime(start , stop):
def toSeconds(timeS tring):
hour, min, sec = map(int, timeString.spli t(':'))
return (hour * 60 + min) * 60 + sec
t_start = toSeconds(start )
t_stop = toSeconds(stop)
d_time = (t_stop - t_start) % 86400
d_time_min, d_time_sec = divmod(d_time, 60)
d_time_hr, d_time_min = divmod(d_time_m in, 60)
return '%dhr %dmin %ssec' % (d_time_hr, d_time_min, d_time_sec)

which is still too verbose for my tastes; I would rewrite it as:

def deltatime(start , stop):
def toSeconds(timeS tring):
hour, min, sec = map(int, timeString.spli t(':'))
return (hour * 60 + min) * 60 + sec
d_time_min, d_time_sec = divmod(toSecond s(stop) - toSeconds(start ),
60)
d_time_hr, d_time_min = divmod(d_time_m in, 60)
return '%dhr %dmin %ssec' % (d_time_hr % 24, d_time_min,
d_time_sec)

delta time = time stop - time start

delta time = time stop - time start

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