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 1.40 2002-12-18 00:15:53 richard Exp $
20 __doc__ = """
21 Date, time and time interval handling.
22 """
24 import time, re, calendar
25 from i18n import _
27 class Date:
28 '''
29 As strings, date-and-time stamps are specified with the date in
30 international standard format (yyyy-mm-dd) joined to the time
31 (hh:mm:ss) by a period ("."). Dates in this form can be easily compared
32 and are fairly readable when printed. An example of a valid stamp is
33 "2000-06-24.13:03:59". We'll call this the "full date format". When
34 Timestamp objects are printed as strings, they appear in the full date
35 format with the time always given in GMT. The full date format is
36 always exactly 19 characters long.
38 For user input, some partial forms are also permitted: the whole time
39 or just the seconds may be omitted; and the whole date may be omitted
40 or just the year may be omitted. If the time is given, the time is
41 interpreted in the user's local time zone. The Date constructor takes
42 care of these conversions. In the following examples, suppose that yyyy
43 is the current year, mm is the current month, and dd is the current day
44 of the month; and suppose that the user is on Eastern Standard Time.
46 "2000-04-17" means <Date 2000-04-17.00:00:00>
47 "01-25" means <Date yyyy-01-25.00:00:00>
48 "2000-04-17.03:45" means <Date 2000-04-17.08:45:00>
49 "08-13.22:13" means <Date yyyy-08-14.03:13:00>
50 "11-07.09:32:43" means <Date yyyy-11-07.14:32:43>
51 "14:25" means <Date yyyy-mm-dd.19:25:00>
52 "8:47:11" means <Date yyyy-mm-dd.13:47:11>
53 "." means "right now"
55 The Date class should understand simple date expressions of the form
56 stamp + interval and stamp - interval. When adding or subtracting
57 intervals involving months or years, the components are handled
58 separately. For example, when evaluating "2000-06-25 + 1m 10d", we
59 first add one month to get 2000-07-25, then add 10 days to get
60 2000-08-04 (rather than trying to decide whether 1m 10d means 38 or 40
61 or 41 days).
63 Example usage:
64 >>> Date(".")
65 <Date 2000-06-26.00:34:02>
66 >>> _.local(-5)
67 "2000-06-25.19:34:02"
68 >>> Date(". + 2d")
69 <Date 2000-06-28.00:34:02>
70 >>> Date("1997-04-17", -5)
71 <Date 1997-04-17.00:00:00>
72 >>> Date("01-25", -5)
73 <Date 2000-01-25.00:00:00>
74 >>> Date("08-13.22:13", -5)
75 <Date 2000-08-14.03:13:00>
76 >>> Date("14:25", -5)
77 <Date 2000-06-25.19:25:00>
79 The date format 'yyyymmddHHMMSS' (year, month, day, hour,
80 minute, second) is the serialisation format returned by the serialise()
81 method, and is accepted as an argument on instatiation.
82 '''
83 def __init__(self, spec='.', offset=0):
84 """Construct a date given a specification and a time zone offset.
86 'spec' is a full date or a partial form, with an optional
87 added or subtracted interval. Or a date 9-tuple.
88 'offset' is the local time zone offset from GMT in hours.
89 """
90 if type(spec) == type(''):
91 self.set(spec, offset=offset)
92 else:
93 y,m,d,H,M,S,x,x,x = spec
94 ts = calendar.timegm((y,m,d,H+offset,M,S,0,0,0))
95 self.year, self.month, self.day, self.hour, self.minute, \
96 self.second, x, x, x = time.gmtime(ts)
98 def addInterval(self, interval):
99 ''' Add the interval to this date, returning the date tuple
100 '''
101 # do the basic calc
102 sign = interval.sign
103 year = self.year + sign * interval.year
104 month = self.month + sign * interval.month
105 day = self.day + sign * interval.day
106 hour = self.hour + sign * interval.hour
107 minute = self.minute + sign * interval.minute
108 second = self.second + sign * interval.second
110 # now cope with under- and over-flow
111 # first do the time
112 while (second < 0 or second > 59 or minute < 0 or minute > 59 or
113 hour < 0 or hour > 59):
114 if second < 0: minute -= 1; second += 60
115 elif second > 59: minute += 1; second -= 60
116 if minute < 0: hour -= 1; minute += 60
117 elif minute > 59: hour += 1; minute -= 60
118 if hour < 0: day -= 1; hour += 24
119 elif hour > 59: day += 1; hour -= 24
121 # fix up the month so we're within range
122 while month < 1 or month > 12:
123 if month < 1: year -= 1; month += 12
124 if month > 12: year += 1; month -= 12
126 # now do the days, now that we know what month we're in
127 mdays = calendar.mdays
128 if month == 2 and calendar.isleap(year): month_days = 29
129 else: month_days = mdays[month]
130 while month < 1 or month > 12 or day < 0 or day > month_days:
131 # now to day under/over
132 if day < 0: month -= 1; day += month_days
133 elif day > month_days: month += 1; day -= month_days
135 # possibly fix up the month so we're within range
136 while month < 1 or month > 12:
137 if month < 1: year -= 1; month += 12
138 if month > 12: year += 1; month -= 12
140 # re-figure the number of days for this month
141 if month == 2 and calendar.isleap(year): month_days = 29
142 else: month_days = mdays[month]
143 return (year, month, day, hour, minute, second, 0, 0, 0)
145 def applyInterval(self, interval):
146 ''' Apply the interval to this date
147 '''
148 self.year, self.month, self.day, self.hour, self.minute, \
149 self.second, x, x, x = self.addInterval(interval)
151 def __add__(self, interval):
152 """Add an interval to this date to produce another date.
153 """
154 return Date(self.addInterval(interval))
156 # deviates from spec to allow subtraction of dates as well
157 def __sub__(self, other):
158 """ Subtract:
159 1. an interval from this date to produce another date.
160 2. a date from this date to produce an interval.
161 """
162 if isinstance(other, Interval):
163 other = Interval(other.get_tuple())
164 other.sign *= -1
165 return self.__add__(other)
167 assert isinstance(other, Date), 'May only subtract Dates or Intervals'
169 # TODO this code will fall over laughing if the dates cross
170 # leap years, phases of the moon, ....
171 a = calendar.timegm((self.year, self.month, self.day, self.hour,
172 self.minute, self.second, 0, 0, 0))
173 b = calendar.timegm((other.year, other.month, other.day,
174 other.hour, other.minute, other.second, 0, 0, 0))
175 diff = a - b
176 if diff < 0:
177 sign = 1
178 diff = -diff
179 else:
180 sign = -1
181 S = diff%60
182 M = (diff/60)%60
183 H = (diff/(60*60))%60
184 if H>1: S = 0
185 d = (diff/(24*60*60))%30
186 if d>1: H = S = M = 0
187 m = (diff/(30*24*60*60))%12
188 if m>1: H = S = M = 0
189 y = (diff/(365*24*60*60))
190 if y>1: d = H = S = M = 0
191 return Interval((y, m, d, H, M, S), sign=sign)
193 def __cmp__(self, other):
194 """Compare this date to another date."""
195 if other is None:
196 return 1
197 for attr in ('year', 'month', 'day', 'hour', 'minute', 'second'):
198 if not hasattr(other, attr):
199 return 1
200 r = cmp(getattr(self, attr), getattr(other, attr))
201 if r: return r
202 return 0
204 def __str__(self):
205 """Return this date as a string in the yyyy-mm-dd.hh:mm:ss format."""
206 return '%4d-%02d-%02d.%02d:%02d:%02d'%(self.year, self.month, self.day,
207 self.hour, self.minute, self.second)
209 def pretty(self, format='%d %B %Y'):
210 ''' print up the date date using a pretty format...
212 Note that if the day is zero, and the day appears first in the
213 format, then the day number will be removed from output.
214 '''
215 str = time.strftime(format, (self.year, self.month, self.day,
216 self.hour, self.minute, self.second, 0, 0, 0))
217 # handle zero day by removing it
218 if format.startswith('%d') and str[0] == '0':
219 return ' ' + str[1:]
220 return str
222 def set(self, spec, offset=0, date_re=re.compile(r'''
223 (((?P<y>\d\d\d\d)-)?((?P<m>\d\d?)-(?P<d>\d\d?))?)? # yyyy-mm-dd
224 (?P<n>\.)? # .
225 (((?P<H>\d?\d):(?P<M>\d\d))?(:(?P<S>\d\d))?)? # hh:mm:ss
226 (?P<o>.+)? # offset
227 ''', re.VERBOSE), serialised_re=re.compile(r'''
228 (\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)
229 ''', re.VERBOSE)):
230 ''' set the date to the value in spec
231 '''
232 m = serialised_re.match(spec)
233 if m is not None:
234 # we're serialised - easy!
235 self.year, self.month, self.day, self.hour, self.minute, \
236 self.second = map(int, m.groups()[:6])
237 return
239 # not serialised data, try usual format
240 m = date_re.match(spec)
241 if m is None:
242 raise ValueError, _('Not a date spec: [[yyyy-]mm-dd].'
243 '[[h]h:mm[:ss]][offset]')
245 info = m.groupdict()
247 # get the current date as our default
248 y,m,d,H,M,S,x,x,x = time.gmtime(time.time())
250 # override year, month, day parts
251 if info['m'] is not None and info['d'] is not None:
252 m = int(info['m'])
253 d = int(info['d'])
254 if info['y'] is not None:
255 y = int(info['y'])
256 # time defaults to 00:00:00 now
257 H = M = S = 0
259 # override hour, minute, second parts
260 if info['H'] is not None and info['M'] is not None:
261 H = int(info['H']) - offset
262 M = int(info['M'])
263 S = 0
264 if info['S'] is not None: S = int(info['S'])
266 # now handle the adjustment of hour
267 ts = calendar.timegm((y,m,d,H,M,S,0,0,0))
268 self.year, self.month, self.day, self.hour, self.minute, \
269 self.second, x, x, x = time.gmtime(ts)
271 if info.get('o', None):
272 self.applyInterval(Interval(info['o']))
274 def __repr__(self):
275 return '<Date %s>'%self.__str__()
277 def local(self, offset):
278 """ Return this date as yyyy-mm-dd.hh:mm:ss in a local time zone.
279 """
280 return Date((self.year, self.month, self.day, self.hour + offset,
281 self.minute, self.second, 0, 0, 0))
283 def get_tuple(self):
284 return (self.year, self.month, self.day, self.hour, self.minute,
285 self.second, 0, 0, 0)
287 def serialise(self):
288 return '%4d%02d%02d%02d%02d%02d'%(self.year, self.month,
289 self.day, self.hour, self.minute, self.second)
291 class Interval:
292 '''
293 Date intervals are specified using the suffixes "y", "m", and "d". The
294 suffix "w" (for "week") means 7 days. Time intervals are specified in
295 hh:mm:ss format (the seconds may be omitted, but the hours and minutes
296 may not).
298 "3y" means three years
299 "2y 1m" means two years and one month
300 "1m 25d" means one month and 25 days
301 "2w 3d" means two weeks and three days
302 "1d 2:50" means one day, two hours, and 50 minutes
303 "14:00" means 14 hours
304 "0:04:33" means four minutes and 33 seconds
306 Example usage:
307 >>> Interval(" 3w 1 d 2:00")
308 <Interval 22d 2:00>
309 >>> Date(". + 2d") + Interval("- 3w")
310 <Date 2000-06-07.00:34:02>
312 Intervals are added/subtracted in order of:
313 seconds, minutes, hours, years, months, days
315 Calculations involving monts (eg '+2m') have no effect on days - only
316 days (or over/underflow from hours/mins/secs) will do that, and
317 days-per-month and leap years are accounted for. Leap seconds are not.
319 The interval format 'syyyymmddHHMMSS' (sign, year, month, day, hour,
320 minute, second) is the serialisation format returned by the serialise()
321 method, and is accepted as an argument on instatiation.
323 TODO: more examples, showing the order of addition operation
324 '''
325 def __init__(self, spec, sign=1):
326 """Construct an interval given a specification."""
327 if type(spec) == type(''):
328 self.set(spec)
329 else:
330 if len(spec) == 7:
331 self.sign, self.year, self.month, self.day, self.hour, \
332 self.minute, self.second = spec
333 else:
334 # old, buggy spec form
335 self.sign = sign
336 self.year, self.month, self.day, self.hour, self.minute, \
337 self.second = spec
339 def __cmp__(self, other):
340 """Compare this interval to another interval."""
341 if other is None:
342 return 1
343 for attr in ('year', 'month', 'day', 'hour', 'minute', 'second'):
344 if not hasattr(other, attr):
345 return 1
346 r = cmp(getattr(self, attr), getattr(other, attr))
347 if r: return r
348 return 0
350 def __str__(self):
351 """Return this interval as a string."""
352 sign = {1:'+', -1:'-'}[self.sign]
353 l = [sign]
354 if self.year: l.append('%sy'%self.year)
355 if self.month: l.append('%sm'%self.month)
356 if self.day: l.append('%sd'%self.day)
357 if self.second:
358 l.append('%d:%02d:%02d'%(self.hour, self.minute, self.second))
359 elif self.hour or self.minute:
360 l.append('%d:%02d'%(self.hour, self.minute))
361 return ' '.join(l)
363 def __add__(self, other):
364 if isinstance(other, Date):
365 # the other is a Date - produce a Date
366 return Date(other.addInterval(self))
367 elif isinstance(other, Interval):
368 # add the other Interval to this one
369 a = self.get_tuple()
370 b = other.get_tuple()
371 if b[0] < 0:
372 i = Interval([x-y for x,y in zip(a[1:],b[1:])])
373 else:
374 i = Interval([x+y for x,y in zip(a[1:],b[1:])])
375 return i
376 # nope, no idea what to do with this other...
377 raise TypeError, "Can't add %r"%other
379 def set(self, spec, interval_re=re.compile('''
380 \s*(?P<s>[-+])? # + or -
381 \s*((?P<y>\d+\s*)y)? # year
382 \s*((?P<m>\d+\s*)m)? # month
383 \s*((?P<w>\d+\s*)w)? # week
384 \s*((?P<d>\d+\s*)d)? # day
385 \s*(((?P<H>\d+):(?P<M>\d+))?(:(?P<S>\d+))?)? # time
386 \s*''', re.VERBOSE), serialised_re=re.compile('''
387 (?P<s>[+-])?1?(?P<y>([ ]{3}\d|\d{4}))(?P<m>\d{2})(?P<d>\d{2})
388 (?P<H>\d{2})(?P<M>\d{2})(?P<S>\d{2})''', re.VERBOSE)):
389 ''' set the date to the value in spec
390 '''
391 self.year = self.month = self.week = self.day = self.hour = \
392 self.minute = self.second = 0
393 self.sign = 1
394 m = serialised_re.match(spec)
395 if not m:
396 m = interval_re.match(spec)
397 if not m:
398 raise ValueError, _('Not an interval spec: [+-] [#y] [#m] [#w] '
399 '[#d] [[[H]H:MM]:SS]')
401 info = m.groupdict()
402 for group, attr in {'y':'year', 'm':'month', 'w':'week', 'd':'day',
403 'H':'hour', 'M':'minute', 'S':'second'}.items():
404 if info.get(group, None) is not None:
405 setattr(self, attr, int(info[group]))
407 if self.week:
408 self.day = self.day + self.week*7
410 if info['s'] is not None:
411 self.sign = {'+':1, '-':-1}[info['s']]
413 def __repr__(self):
414 return '<Interval %s>'%self.__str__()
416 def pretty(self):
417 ''' print up the date date using one of these nice formats..
418 '''
419 if self.year:
420 if self.year == 1:
421 return _('1 year')
422 else:
423 return _('%(number)s years')%{'number': self.year}
424 elif self.month or self.day > 13:
425 days = (self.month * 30) + self.day
426 if days > 28:
427 if int(days/30) > 1:
428 s = _('%(number)s months')%{'number': int(days/30)}
429 else:
430 s = _('1 month')
431 else:
432 s = _('%(number)s weeks')%{'number': int(days/7)}
433 elif self.day > 7:
434 s = _('1 week')
435 elif self.day > 1:
436 s = _('%(number)s days')%{'number': self.day}
437 elif self.day == 1 or self.hour > 12:
438 if self.sign > 0:
439 return _('tomorrow')
440 else:
441 return _('yesterday')
442 elif self.hour > 1:
443 s = _('%(number)s hours')%{'number': self.hour}
444 elif self.hour == 1:
445 if self.minute < 15:
446 s = _('an hour')
447 elif self.minute/15 == 2:
448 s = _('1 1/2 hours')
449 else:
450 s = _('1 %(number)s/4 hours')%{'number': self.minute/15}
451 elif self.minute < 1:
452 if self.sign > 0:
453 return _('in a moment')
454 else:
455 return _('just now')
456 elif self.minute == 1:
457 s = _('1 minute')
458 elif self.minute < 15:
459 s = _('%(number)s minutes')%{'number': self.minute}
460 elif int(self.minute/15) == 2:
461 s = _('1/2 an hour')
462 else:
463 s = _('%(number)s/4 hour')%{'number': int(self.minute/15)}
464 return s
466 def get_tuple(self):
467 return (self.sign, self.year, self.month, self.day, self.hour,
468 self.minute, self.second)
470 def serialise(self):
471 sign = self.sign > 0 and '+' or '-'
472 return '%s%04d%02d%02d%02d%02d%02d'%(sign, self.year, self.month,
473 self.day, self.hour, self.minute, self.second)
476 def test():
477 intervals = (" 3w 1 d 2:00", " + 2d", "3w")
478 for interval in intervals:
479 print '>>> Interval("%s")'%interval
480 print `Interval(interval)`
482 dates = (".", "2000-06-25.19:34:02", ". + 2d", "1997-04-17", "01-25",
483 "08-13.22:13", "14:25")
484 for date in dates:
485 print '>>> Date("%s")'%date
486 print `Date(date)`
488 sums = ((". + 2d", "3w"), (".", " 3w 1 d 2:00"))
489 for date, interval in sums:
490 print '>>> Date("%s") + Interval("%s")'%(date, interval)
491 print `Date(date) + Interval(interval)`
493 if __name__ == '__main__':
494 test()
496 # vim: set filetype=python ts=4 sw=4 et si