1 #
2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
3 # This module is free software, and you may redistribute it and/or modify
4 # under the same terms as Python, so long as this copyright message and
5 # disclaimer are retained in their original form.
6 #
7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
10 # POSSIBILITY OF SUCH DAMAGE.
11 #
12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
14 # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
17 #
18 # $Id: date.py,v 1.59 2003-12-05 03:28:38 richard Exp $
20 __doc__ = """
21 Date, time and time interval handling.
22 """
24 import time, re, calendar, types
25 from i18n import _
27 def _add_granularity(src, order, value = 1):
28 '''Increment first non-None value in src dictionary ordered by 'order'
29 parameter
30 '''
31 for gran in order:
32 if src[gran]:
33 src[gran] = int(src[gran]) + value
34 break
36 class Date:
37 '''
38 As strings, date-and-time stamps are specified with the date in
39 international standard format (yyyy-mm-dd) joined to the time
40 (hh:mm:ss) by a period ("."). Dates in this form can be easily compared
41 and are fairly readable when printed. An example of a valid stamp is
42 "2000-06-24.13:03:59". We'll call this the "full date format". When
43 Timestamp objects are printed as strings, they appear in the full date
44 format with the time always given in GMT. The full date format is
45 always exactly 19 characters long.
47 For user input, some partial forms are also permitted: the whole time
48 or just the seconds may be omitted; and the whole date may be omitted
49 or just the year may be omitted. If the time is given, the time is
50 interpreted in the user's local time zone. The Date constructor takes
51 care of these conversions. In the following examples, suppose that yyyy
52 is the current year, mm is the current month, and dd is the current day
53 of the month; and suppose that the user is on Eastern Standard Time.
55 "2000-04-17" means <Date 2000-04-17.00:00:00>
56 "01-25" means <Date yyyy-01-25.00:00:00>
57 "2000-04-17.03:45" means <Date 2000-04-17.08:45:00>
58 "08-13.22:13" means <Date yyyy-08-14.03:13:00>
59 "11-07.09:32:43" means <Date yyyy-11-07.14:32:43>
60 "14:25" means <Date yyyy-mm-dd.19:25:00>
61 "8:47:11" means <Date yyyy-mm-dd.13:47:11>
62 "2003" means <Date 2003-01-01.00:00:00>
63 "2003-06" means <Date 2003-06-01.00:00:00>
64 "." means "right now"
66 The Date class should understand simple date expressions of the form
67 stamp + interval and stamp - interval. When adding or subtracting
68 intervals involving months or years, the components are handled
69 separately. For example, when evaluating "2000-06-25 + 1m 10d", we
70 first add one month to get 2000-07-25, then add 10 days to get
71 2000-08-04 (rather than trying to decide whether 1m 10d means 38 or 40
72 or 41 days).
74 Example usage:
75 >>> Date(".")
76 <Date 2000-06-26.00:34:02>
77 >>> _.local(-5)
78 "2000-06-25.19:34:02"
79 >>> Date(". + 2d")
80 <Date 2000-06-28.00:34:02>
81 >>> Date("1997-04-17", -5)
82 <Date 1997-04-17.00:00:00>
83 >>> Date("01-25", -5)
84 <Date 2000-01-25.00:00:00>
85 >>> Date("08-13.22:13", -5)
86 <Date 2000-08-14.03:13:00>
87 >>> Date("14:25", -5)
88 <Date 2000-06-25.19:25:00>
90 The date format 'yyyymmddHHMMSS' (year, month, day, hour,
91 minute, second) is the serialisation format returned by the serialise()
92 method, and is accepted as an argument on instatiation.
93 '''
95 def __init__(self, spec='.', offset=0, add_granularity=0):
96 """Construct a date given a specification and a time zone offset.
98 'spec' is a full date or a partial form, with an optional
99 added or subtracted interval. Or a date 9-tuple.
100 'offset' is the local time zone offset from GMT in hours.
101 """
102 if type(spec) == type(''):
103 self.set(spec, offset=offset, add_granularity=add_granularity)
104 else:
105 y,m,d,H,M,S,x,x,x = spec
106 ts = calendar.timegm((y,m,d,H+offset,M,S,0,0,0))
107 self.year, self.month, self.day, self.hour, self.minute, \
108 self.second, x, x, x = time.gmtime(ts)
110 usagespec='[yyyy]-[mm]-[dd].[H]H:MM[:SS][offset]'
111 def set(self, spec, offset=0, date_re=re.compile(r'''
112 ((?P<y>\d\d\d\d)([/-](?P<m>\d\d?)([/-](?P<d>\d\d?))?)? # yyyy[-mm[-dd]]
113 |(?P<a>\d\d?)[/-](?P<b>\d\d?))? # or mm-dd
114 (?P<n>\.)? # .
115 (((?P<H>\d?\d):(?P<M>\d\d))?(:(?P<S>\d\d))?)? # hh:mm:ss
116 (?P<o>.+)? # offset
117 ''', re.VERBOSE), serialised_re=re.compile(r'''
118 (\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)
119 ''', re.VERBOSE), add_granularity=0):
120 ''' set the date to the value in spec
121 '''
123 m = serialised_re.match(spec)
124 if m is not None:
125 # we're serialised - easy!
126 self.year, self.month, self.day, self.hour, self.minute, \
127 self.second = map(int, m.groups()[:6])
128 return
130 # not serialised data, try usual format
131 m = date_re.match(spec)
132 if m is None:
133 raise ValueError, _('Not a date spec: %s' % self.usagespec)
135 info = m.groupdict()
137 if add_granularity:
138 _add_granularity(info, 'SMHdmyab')
140 # get the current date as our default
141 y,m,d,H,M,S,x,x,x = time.gmtime(time.time())
143 if info['y'] is not None or info['a'] is not None:
144 if info['y'] is not None:
145 y = int(info['y'])
146 m,d = (1,1)
147 if info['m'] is not None:
148 m = int(info['m'])
149 if info['d'] is not None:
150 d = int(info['d'])
151 if info['a'] is not None:
152 m = int(info['a'])
153 d = int(info['b'])
154 H = -offset
155 M = S = 0
157 # override hour, minute, second parts
158 if info['H'] is not None and info['M'] is not None:
159 H = int(info['H']) - offset
160 M = int(info['M'])
161 S = 0
162 if info['S'] is not None: S = int(info['S'])
164 if add_granularity:
165 S = S - 1
167 # now handle the adjustment of hour
168 ts = calendar.timegm((y,m,d,H,M,S,0,0,0))
169 self.year, self.month, self.day, self.hour, self.minute, \
170 self.second, x, x, x = time.gmtime(ts)
172 if info.get('o', None):
173 try:
174 self.applyInterval(Interval(info['o'], allowdate=0))
175 except ValueError:
176 raise ValueError, _('Not a date spec: %s' % self.usagespec)
178 def addInterval(self, interval):
179 ''' Add the interval to this date, returning the date tuple
180 '''
181 # do the basic calc
182 sign = interval.sign
183 year = self.year + sign * interval.year
184 month = self.month + sign * interval.month
185 day = self.day + sign * interval.day
186 hour = self.hour + sign * interval.hour
187 minute = self.minute + sign * interval.minute
188 second = self.second + sign * interval.second
190 # now cope with under- and over-flow
191 # first do the time
192 while (second < 0 or second > 59 or minute < 0 or minute > 59 or
193 hour < 0 or hour > 23):
194 if second < 0: minute -= 1; second += 60
195 elif second > 59: minute += 1; second -= 60
196 if minute < 0: hour -= 1; minute += 60
197 elif minute > 59: hour += 1; minute -= 60
198 if hour < 0: day -= 1; hour += 24
199 elif hour > 23: day += 1; hour -= 24
201 # fix up the month so we're within range
202 while month < 1 or month > 12:
203 if month < 1: year -= 1; month += 12
204 if month > 12: year += 1; month -= 12
206 # now do the days, now that we know what month we're in
207 def get_mdays(year, month):
208 if month == 2 and calendar.isleap(year): return 29
209 else: return calendar.mdays[month]
211 while month < 1 or month > 12 or day < 1 or day > get_mdays(year,month):
212 # now to day under/over
213 if day < 1:
214 # When going backwards, decrement month, then increment days
215 month -= 1
216 day += get_mdays(year,month)
217 elif day > get_mdays(year,month):
218 # When going forwards, decrement days, then increment month
219 day -= get_mdays(year,month)
220 month += 1
222 # possibly fix up the month so we're within range
223 while month < 1 or month > 12:
224 if month < 1: year -= 1; month += 12 ; day += 31
225 if month > 12: year += 1; month -= 12
227 return (year, month, day, hour, minute, second, 0, 0, 0)
229 def differenceDate(self, other):
230 "Return the difference between this date and another date"
232 def applyInterval(self, interval):
233 ''' Apply the interval to this date
234 '''
235 self.year, self.month, self.day, self.hour, self.minute, \
236 self.second, x, x, x = self.addInterval(interval)
238 def __add__(self, interval):
239 """Add an interval to this date to produce another date.
240 """
241 return Date(self.addInterval(interval))
243 # deviates from spec to allow subtraction of dates as well
244 def __sub__(self, other):
245 """ Subtract:
246 1. an interval from this date to produce another date.
247 2. a date from this date to produce an interval.
248 """
249 if isinstance(other, Interval):
250 other = Interval(other.get_tuple())
251 other.sign *= -1
252 return self.__add__(other)
254 assert isinstance(other, Date), 'May only subtract Dates or Intervals'
256 return self.dateDelta(other)
258 def dateDelta(self, other):
259 """ Produce an Interval of the difference between this date
260 and another date. Only returns days:hours:minutes:seconds.
261 """
262 # Returning intervals larger than a day is almost
263 # impossible - months, years, weeks, are all so imprecise.
264 a = calendar.timegm((self.year, self.month, self.day, self.hour,
265 self.minute, self.second, 0, 0, 0))
266 b = calendar.timegm((other.year, other.month, other.day,
267 other.hour, other.minute, other.second, 0, 0, 0))
268 diff = a - b
269 if diff > 0:
270 sign = 1
271 else:
272 sign = -1
273 diff = -diff
274 S = diff%60
275 M = (diff/60)%60
276 H = (diff/(60*60))%24
277 d = diff/(24*60*60)
278 return Interval((0, 0, d, H, M, S), sign=sign)
280 def __cmp__(self, other):
281 """Compare this date to another date."""
282 if other is None:
283 return 1
284 for attr in ('year', 'month', 'day', 'hour', 'minute', 'second'):
285 if not hasattr(other, attr):
286 return 1
287 r = cmp(getattr(self, attr), getattr(other, attr))
288 if r: return r
289 return 0
291 def __str__(self):
292 """Return this date as a string in the yyyy-mm-dd.hh:mm:ss format."""
293 return '%4d-%02d-%02d.%02d:%02d:%02d'%(self.year, self.month, self.day,
294 self.hour, self.minute, self.second)
296 def pretty(self, format='%d %B %Y'):
297 ''' print up the date date using a pretty format...
299 Note that if the day is zero, and the day appears first in the
300 format, then the day number will be removed from output.
301 '''
302 str = time.strftime(format, (self.year, self.month, self.day,
303 self.hour, self.minute, self.second, 0, 0, 0))
304 # handle zero day by removing it
305 if format.startswith('%d') and str[0] == '0':
306 return ' ' + str[1:]
307 return str
309 def __repr__(self):
310 return '<Date %s>'%self.__str__()
312 def local(self, offset):
313 """ Return this date as yyyy-mm-dd.hh:mm:ss in a local time zone.
314 """
315 return Date((self.year, self.month, self.day, self.hour + offset,
316 self.minute, self.second, 0, 0, 0))
318 def get_tuple(self):
319 return (self.year, self.month, self.day, self.hour, self.minute,
320 self.second, 0, 0, 0)
322 def serialise(self):
323 return '%4d%02d%02d%02d%02d%02d'%(self.year, self.month,
324 self.day, self.hour, self.minute, self.second)
326 def timestamp(self):
327 ''' return a UNIX timestamp for this date '''
328 return calendar.timegm((self.year, self.month, self.day, self.hour,
329 self.minute, self.second, 0, 0, 0))
331 class Interval:
332 '''
333 Date intervals are specified using the suffixes "y", "m", and "d". The
334 suffix "w" (for "week") means 7 days. Time intervals are specified in
335 hh:mm:ss format (the seconds may be omitted, but the hours and minutes
336 may not).
338 "3y" means three years
339 "2y 1m" means two years and one month
340 "1m 25d" means one month and 25 days
341 "2w 3d" means two weeks and three days
342 "1d 2:50" means one day, two hours, and 50 minutes
343 "14:00" means 14 hours
344 "0:04:33" means four minutes and 33 seconds
346 Example usage:
347 >>> Interval(" 3w 1 d 2:00")
348 <Interval + 22d 2:00>
349 >>> Date(". + 2d") + Interval("- 3w")
350 <Date 2000-06-07.00:34:02>
351 >>> Interval('1:59:59') + Interval('00:00:01')
352 <Interval + 2:00>
353 >>> Interval('2:00') + Interval('- 00:00:01')
354 <Interval + 1:59:59>
355 >>> Interval('1y')/2
356 <Interval + 6m>
357 >>> Interval('1:00')/2
358 <Interval + 0:30>
359 >>> Interval('2003-03-18')
360 <Interval + [number of days between now and 2003-03-18]>
361 >>> Interval('-4d 2003-03-18')
362 <Interval + [number of days between now and 2003-03-14]>
364 Interval arithmetic is handled in a couple of special ways, trying
365 to cater for the most common cases. Fundamentally, Intervals which
366 have both date and time parts will result in strange results in
367 arithmetic - because of the impossibility of handling day->month->year
368 over- and under-flows. Intervals may also be divided by some number.
370 Intervals are added to Dates in order of:
371 seconds, minutes, hours, years, months, days
373 Calculations involving months (eg '+2m') have no effect on days - only
374 days (or over/underflow from hours/mins/secs) will do that, and
375 days-per-month and leap years are accounted for. Leap seconds are not.
377 The interval format 'syyyymmddHHMMSS' (sign, year, month, day, hour,
378 minute, second) is the serialisation format returned by the serialise()
379 method, and is accepted as an argument on instatiation.
381 TODO: more examples, showing the order of addition operation
382 '''
383 def __init__(self, spec, sign=1, allowdate=1, add_granularity=0):
384 """Construct an interval given a specification."""
385 if type(spec) == type(''):
386 self.set(spec, allowdate=allowdate, add_granularity=add_granularity)
387 else:
388 if len(spec) == 7:
389 self.sign, self.year, self.month, self.day, self.hour, \
390 self.minute, self.second = spec
391 else:
392 # old, buggy spec form
393 self.sign = sign
394 self.year, self.month, self.day, self.hour, self.minute, \
395 self.second = spec
397 def set(self, spec, allowdate=1, interval_re=re.compile('''
398 \s*(?P<s>[-+])? # + or -
399 \s*((?P<y>\d+\s*)y)? # year
400 \s*((?P<m>\d+\s*)m)? # month
401 \s*((?P<w>\d+\s*)w)? # week
402 \s*((?P<d>\d+\s*)d)? # day
403 \s*(((?P<H>\d+):(?P<M>\d+))?(:(?P<S>\d+))?)? # time
404 \s*(?P<D>
405 (\d\d\d\d[/-])?(\d\d?)?[/-](\d\d?)? # [yyyy-]mm-dd
406 \.? # .
407 (\d?\d:\d\d)?(:\d\d)? # hh:mm:ss
408 )?''', re.VERBOSE), serialised_re=re.compile('''
409 (?P<s>[+-])?1?(?P<y>([ ]{3}\d|\d{4}))(?P<m>\d{2})(?P<d>\d{2})
410 (?P<H>\d{2})(?P<M>\d{2})(?P<S>\d{2})''', re.VERBOSE),
411 add_granularity=0):
412 ''' set the date to the value in spec
413 '''
414 self.year = self.month = self.week = self.day = self.hour = \
415 self.minute = self.second = 0
416 self.sign = 1
417 m = serialised_re.match(spec)
418 if not m:
419 m = interval_re.match(spec)
420 if not m:
421 raise ValueError, _('Not an interval spec: [+-] [#y] [#m] [#w] '
422 '[#d] [[[H]H:MM]:SS] [date spec]')
423 else:
424 allowdate = 0
426 # pull out all the info specified
427 info = m.groupdict()
428 if add_granularity:
429 _add_granularity(info, 'SMHdwmy', (info['s']=='-' and -1 or 1))
431 valid = 0
432 for group, attr in {'y':'year', 'm':'month', 'w':'week', 'd':'day',
433 'H':'hour', 'M':'minute', 'S':'second'}.items():
434 if info.get(group, None) is not None:
435 valid = 1
436 setattr(self, attr, int(info[group]))
438 # make sure it's valid
439 if not valid and not info['D']:
440 raise ValueError, _('Not an interval spec: [+-] [#y] [#m] [#w] '
441 '[#d] [[[H]H:MM]:SS]')
443 if self.week:
444 self.day = self.day + self.week*7
446 if info['s'] is not None:
447 self.sign = {'+':1, '-':-1}[info['s']]
449 # use a date spec if one is given
450 if allowdate and info['D'] is not None:
451 now = Date('.')
452 date = Date(info['D'])
453 # if no time part was specified, nuke it in the "now" date
454 if not date.hour or date.minute or date.second:
455 now.hour = now.minute = now.second = 0
456 if date != now:
457 y = now - (date + self)
458 self.__init__(y.get_tuple())
460 def __cmp__(self, other):
461 """Compare this interval to another interval."""
462 if other is None:
463 # we are always larger than None
464 return 1
465 for attr in 'sign year month day hour minute second'.split():
466 r = cmp(getattr(self, attr), getattr(other, attr))
467 if r:
468 return r
469 return 0
471 def __str__(self):
472 """Return this interval as a string."""
473 l = []
474 if self.year: l.append('%sy'%self.year)
475 if self.month: l.append('%sm'%self.month)
476 if self.day: l.append('%sd'%self.day)
477 if self.second:
478 l.append('%d:%02d:%02d'%(self.hour, self.minute, self.second))
479 elif self.hour or self.minute:
480 l.append('%d:%02d'%(self.hour, self.minute))
481 if l:
482 l.insert(0, {1:'+', -1:'-'}[self.sign])
483 return ' '.join(l)
485 def __add__(self, other):
486 if isinstance(other, Date):
487 # the other is a Date - produce a Date
488 return Date(other.addInterval(self))
489 elif isinstance(other, Interval):
490 # add the other Interval to this one
491 a = self.get_tuple()
492 as = a[0]
493 b = other.get_tuple()
494 bs = b[0]
495 i = [as*x + bs*y for x,y in zip(a[1:],b[1:])]
496 i.insert(0, 1)
497 i = fixTimeOverflow(i)
498 return Interval(i)
499 # nope, no idea what to do with this other...
500 raise TypeError, "Can't add %r"%other
502 def __sub__(self, other):
503 if isinstance(other, Date):
504 # the other is a Date - produce a Date
505 interval = Interval(self.get_tuple())
506 interval.sign *= -1
507 return Date(other.addInterval(interval))
508 elif isinstance(other, Interval):
509 # add the other Interval to this one
510 a = self.get_tuple()
511 as = a[0]
512 b = other.get_tuple()
513 bs = b[0]
514 i = [as*x - bs*y for x,y in zip(a[1:],b[1:])]
515 i.insert(0, 1)
516 i = fixTimeOverflow(i)
517 return Interval(i)
518 # nope, no idea what to do with this other...
519 raise TypeError, "Can't add %r"%other
521 def __div__(self, other):
522 """ Divide this interval by an int value.
524 Can't divide years and months sensibly in the _same_
525 calculation as days/time, so raise an error in that situation.
526 """
527 try:
528 other = float(other)
529 except TypeError:
530 raise ValueError, "Can only divide Intervals by numbers"
532 y, m, d, H, M, S = (self.year, self.month, self.day,
533 self.hour, self.minute, self.second)
534 if y or m:
535 if d or H or M or S:
536 raise ValueError, "Can't divide Interval with date and time"
537 months = self.year*12 + self.month
538 months *= self.sign
540 months = int(months/other)
542 sign = months<0 and -1 or 1
543 m = months%12
544 y = months / 12
545 return Interval((sign, y, m, 0, 0, 0, 0))
547 else:
548 # handle a day/time division
549 seconds = S + M*60 + H*60*60 + d*60*60*24
550 seconds *= self.sign
552 seconds = int(seconds/other)
554 sign = seconds<0 and -1 or 1
555 seconds *= sign
556 S = seconds%60
557 seconds /= 60
558 M = seconds%60
559 seconds /= 60
560 H = seconds%24
561 d = seconds / 24
562 return Interval((sign, 0, 0, d, H, M, S))
564 def __repr__(self):
565 return '<Interval %s>'%self.__str__()
567 def pretty(self):
568 ''' print up the date date using one of these nice formats..
569 '''
570 if self.year:
571 if self.year == 1:
572 s = _('1 year')
573 else:
574 s = _('%(number)s years')%{'number': self.year}
575 elif self.month or self.day > 13:
576 days = (self.month * 30) + self.day
577 if days > 28:
578 if int(days/30) > 1:
579 s = _('%(number)s months')%{'number': int(days/30)}
580 else:
581 s = _('1 month')
582 else:
583 s = _('%(number)s weeks')%{'number': int(days/7)}
584 elif self.day > 7:
585 s = _('1 week')
586 elif self.day > 1:
587 s = _('%(number)s days')%{'number': self.day}
588 elif self.day == 1 or self.hour > 12:
589 if self.sign > 0:
590 return _('tomorrow')
591 else:
592 return _('yesterday')
593 elif self.hour > 1:
594 s = _('%(number)s hours')%{'number': self.hour}
595 elif self.hour == 1:
596 if self.minute < 15:
597 s = _('an hour')
598 elif self.minute/15 == 2:
599 s = _('1 1/2 hours')
600 else:
601 s = _('1 %(number)s/4 hours')%{'number': self.minute/15}
602 elif self.minute < 1:
603 if self.sign > 0:
604 return _('in a moment')
605 else:
606 return _('just now')
607 elif self.minute == 1:
608 s = _('1 minute')
609 elif self.minute < 15:
610 s = _('%(number)s minutes')%{'number': self.minute}
611 elif int(self.minute/15) == 2:
612 s = _('1/2 an hour')
613 else:
614 s = _('%(number)s/4 hour')%{'number': int(self.minute/15)}
615 if self.sign < 0:
616 s = s + _(' ago')
617 else:
618 s = _('in ') + s
619 return s
621 def get_tuple(self):
622 return (self.sign, self.year, self.month, self.day, self.hour,
623 self.minute, self.second)
625 def serialise(self):
626 sign = self.sign > 0 and '+' or '-'
627 return '%s%04d%02d%02d%02d%02d%02d'%(sign, self.year, self.month,
628 self.day, self.hour, self.minute, self.second)
630 def fixTimeOverflow(time):
631 """ Handle the overflow in the time portion (H, M, S) of "time":
632 (sign, y,m,d,H,M,S)
634 Overflow and underflow will at most affect the _days_ portion of
635 the date. We do not overflow days to months as we don't know _how_
636 to, generally.
637 """
638 # XXX we could conceivably use this function for handling regular dates
639 # XXX too - we just need to interrogate the month/year for the day
640 # XXX overflow...
642 sign, y, m, d, H, M, S = time
643 seconds = sign * (S + M*60 + H*60*60 + d*60*60*24)
644 if seconds:
645 sign = seconds<0 and -1 or 1
646 seconds *= sign
647 S = seconds%60
648 seconds /= 60
649 M = seconds%60
650 seconds /= 60
651 H = seconds%24
652 d = seconds / 24
653 else:
654 months = y*12 + m
655 sign = months<0 and -1 or 1
656 months *= sign
657 m = months%12
658 y = months/12
660 return (sign, y, m, d, H, M, S)
662 class Range:
663 """
664 Represents range between two values
665 Ranges can be created using one of theese two alternative syntaxes:
667 1. Native english syntax:
668 [[From] <value>][ To <value>]
669 Keywords "From" and "To" are case insensitive. Keyword "From" is optional.
671 2. "Geek" syntax:
672 [<value>][; <value>]
674 Either first or second <value> can be omitted in both syntaxes.
676 Examples (consider local time is Sat Mar 8 22:07:48 EET 2003):
677 >>> Range("from 2-12 to 4-2")
678 <Range from 2003-02-12.00:00:00 to 2003-04-02.00:00:00>
680 >>> Range("18:00 TO +2m")
681 <Range from 2003-03-08.18:00:00 to 2003-05-08.20:07:48>
683 >>> Range("12:00")
684 <Range from 2003-03-08.12:00:00 to None>
686 >>> Range("tO +3d")
687 <Range from None to 2003-03-11.20:07:48>
689 >>> Range("2002-11-10; 2002-12-12")
690 <Range from 2002-11-10.00:00:00 to 2002-12-12.00:00:00>
692 >>> Range("; 20:00 +1d")
693 <Range from None to 2003-03-09.20:00:00>
695 """
696 def __init__(self, spec, Type, allow_granularity=1, **params):
697 """Initializes Range of type <Type> from given <spec> string.
699 Sets two properties - from_value and to_value. None assigned to any of
700 this properties means "infinitum" (-infinitum to from_value and
701 +infinitum to to_value)
703 The Type parameter here should be class itself (e.g. Date), not a
704 class instance.
706 """
707 self.range_type = Type
708 re_range = r'(?:^|from(.+?))(?:to(.+?)$|$)'
709 re_geek_range = r'(?:^|(.+?));(?:(.+?)$|$)'
710 # Check which syntax to use
711 if spec.find(';') == -1:
712 # Native english
713 mch_range = re.search(re_range, spec.strip(), re.IGNORECASE)
714 else:
715 # Geek
716 mch_range = re.search(re_geek_range, spec.strip())
717 if mch_range:
718 self.from_value, self.to_value = mch_range.groups()
719 if self.from_value:
720 self.from_value = Type(self.from_value.strip(), **params)
721 if self.to_value:
722 self.to_value = Type(self.to_value.strip(), **params)
723 else:
724 if allow_granularity:
725 self.from_value = Type(spec, **params)
726 self.to_value = Type(spec, add_granularity=1, **params)
727 else:
728 raise ValueError, "Invalid range"
730 def __str__(self):
731 return "from %s to %s" % (self.from_value, self.to_value)
733 def __repr__(self):
734 return "<Range %s>" % self.__str__()
736 def test_range():
737 rspecs = ("from 2-12 to 4-2", "from 18:00 TO +2m", "12:00;", "tO +3d",
738 "2002-11-10; 2002-12-12", "; 20:00 +1d", '2002-10-12')
739 rispecs = ('from -1w 2d 4:32 to 4d', '-2w 1d')
740 for rspec in rspecs:
741 print '>>> Range("%s")' % rspec
742 print `Range(rspec, Date)`
743 print
744 for rspec in rispecs:
745 print '>>> Range("%s")' % rspec
746 print `Range(rspec, Interval)`
747 print
749 def test():
750 intervals = (" 3w 1 d 2:00", " + 2d", "3w")
751 for interval in intervals:
752 print '>>> Interval("%s")'%interval
753 print `Interval(interval)`
755 dates = (".", "2000-06-25.19:34:02", ". + 2d", "1997-04-17", "01-25",
756 "08-13.22:13", "14:25", '2002-12')
757 for date in dates:
758 print '>>> Date("%s")'%date
759 print `Date(date)`
761 sums = ((". + 2d", "3w"), (".", " 3w 1 d 2:00"))
762 for date, interval in sums:
763 print '>>> Date("%s") + Interval("%s")'%(date, interval)
764 print `Date(date) + Interval(interval)`
766 if __name__ == '__main__':
767 test()
769 # vim: set filetype=python ts=4 sw=4 et si