[Tutor] time comparison question

[Brian van den Broek]

Hi all,

I'm trying to build some Python 2.3.4 code which will determine if the 
actual time when it is run is after the date and time specified in some 
data. I want my data to be able to specify the target date/time in a 
various levels of detail. I.e., I want 2004-11-28 13:25, 2004-11-28, 
11-28, 11-28 13:25 to all be accepted.

My first thought was to get the current time via time.time() and then 
parse my target date into a struct_time tuple to pass to time.mktime(), 
run a comparison and be done. However, a struct_time tuple has data that 
I won't know, given one of my target dates. I can make sensible dummies 
for seconds (as well as year, hours and minutes when my target does not 
specify them), and I know that the time module will try to make a 
reasonable guess if given -1 for the DST element. But for 
a_struct_time_tuple[-3:-1], I'd just be guessing at the weekday and day 
of year. This leads to two questions:

1) As I write, time.asctime() gives 'Fri Nov 26 04:32:18 2004' for a 
time.localtime() of (2004, 11, 26, 4, 32, 18, 4, 331, 0). If I were 
filling out a target date of 2004-11-26 04:32, I might well end up 
passing something like (2004, 11, 26, 4, 32, 18, 6, 328, 0) to 
time.mktime() for the result 'Sun Nov 26 04:32:18 2004'. If I am not 
actually using the weekday information, I suspect that I can just ignore 
the incorrect 'Sun'. But I feel better checking -- is anything going to 
break by giving struct_time elements that don't make sense (provided of 
course I am not myself explicitly drawing upon them)?

2) Naturally, these worries lead me to think that there must be a better 
way. I took a brief look at the datetime module, thinking it was a 
natural place to find such tools. But it is all in terms of classes. 
Sadly, I am still not too comfortable with doing things via OOP, so I'd 
prefer a procedural (if that's the right term for a program with 
functions but no classes) way. Is there a cleaner, non-class employing, 
way of meeting my goal of finding out if a date of the form YYYY-MM-DD 
is in the future, present, or past? (If it matters, I am on Windows.)

Thanks for any links, etc.

Best to all,

Brian vdB