how to compare date time in web2py?

[Amit]

Hi,
I have some records in a table and each record is having one field of type datetime [fromat : 2012-07-19 23:12:0 (YYYY-MM-DD HH:MM:SS)], table structure is:

Emp_ID
Emp_Name
Emp_Address
Emp_Salary
updated_on(Type: datetime)

periodically getting data against each Emp_ID and updating to the particular record, every 20 mins data has to be updated for each Emp_ID, for e.g : suppose for one Emp_ID data has updated on 2012-07-19 10:10:00 then again it has to update on 2012-07-19 10:30:00 etc...

and if data is not updated in 20 mins then one scheduler will verify against the updated_on column value and inform user that data has not updated  for particular employee.

Problem facing:
How to compare current datetime with updated_on coulmn value in web2py? can anybody please share me the code to achieve the same?

[Niphlod]

current datetime is:
request.now

or
import datetime
datetime.datetime.now()

[Andrew]

I'm not sure if web2py has something built-in to do this calculation but for other similar issues in the past I've just converted my dates to epoch and done the necessary math to see the difference between the two date-times. 

[Jonathan Lundell]

On 20 Jul 2012, at 6:19 AM, Andrew wrote:

I'm not sure if web2py has something built-in to do this calculation but for other similar issues in the past I've just converted my dates to epoch and done the necessary math to see the difference between the two date-times. 

web2py ordinarily deals with datetime fields as Python datetime objects, which can just be compared (with due allowance for timezones). request.now has the current local time as a datetime; request.utcnow has UTC.

I use epoch dates myself in some cases, in particular to communicate with iOS clients through JSON, passing them as integers. The Python docs have quite a bit of material on manipulating dates, though it's a bit confusing in places. The modules of most interest are datetime, time and calendar.

[Ovidio Marinho]

Difference of Two Dates

#----------------------------- # Dates produce timedeltas when subtracted. diff = date2 - date1 diff = datetime.date(year1, month1, day1) - datetime.date(year2, month2, day2) #----------------------------- bree = datetime.datetime(1981, 6, 16, 4, 35, 25) nat = datetime.datetime(1973, 1, 18, 3, 45, 50) difference = bree - nat print "There were", difference, "minutes between Nat and Bree" #=> There were 3071 days, 0:49:35 between Nat and Bree weeks, days = divmod(difference.days, 7) minutes, seconds = divmod(difference.seconds, 60) hours, minutes = divmod(minutes, 60) print "%d weeks, %d days, %d:%d:%d" % (weeks, days, hours, minutes, seconds) #=> 438 weeks, 5 days, 0:49:35 #----------------------------- print "There were", difference.days, "days between Bree and Nat." #=> There were 3071 days between bree and nat

      

Origin: http://pleac.sourceforge.net/pleac_python/datesandtimes.html

       Ovidio Marinho Falcao Neto

                Web Developer
             ovid...@gmail.com 

          ovidio...@itjp.net.br

                 ITJP - itjp.net.br
               83   8826 9088 - Oi

               83   9334 0266 - Claro
                        Brasil

              

2012/7/20 Jonathan Lundell <jlun...@pobox.com>

--
 
 
 

[akshay...@gmail.com]

You can compare time here by using the relational operators. Access the current time by using 'request.now' (its value will be in same format as 'update_on' field of your table) then you can just compare it as :

if (dbquery).updated_time > request.now:
    //do something

[Peter]

I had some fun with this

max_age_allowed = 20 * 60  # total seconds in 20 minutes
update_age = request.now - person.created_on  # Duration in datetime format since record created
update_age = update_age.total_seconds()       # Duration converted to seconds
print "It is %s seconds since record created (threshold is %s seconds)" % (update_age,max_age_allowed )
if update_age > max_age_allowed:
    print 'Do something'
else:
    print 'Nothing to do here'

output

It is 2102030.41814 seconds since record created (threshold is 1200 seconds)
Do something

Hope this helps.