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 1.36 2002-10-12 23:10:36 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/time using the offset
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: y = int(info['y'])
255 H = M = S = 0
257 # override hour, minute, second parts
258 if info['H'] is not None and info['M'] is not None:
259 H = int(info['H']) - offset
260 M = int(info['M'])
261 S = 0
262 if info['S'] is not None: S = int(info['S'])
264 # now handle the adjustment of hour
265 ts = calendar.timegm((y,m,d,H,M,S,0,0,0))
266 self.year, self.month, self.day, self.hour, self.minute, \
267 self.second, x, x, x = time.gmtime(ts)
269 if info.get('o', None):
270 self.applyInterval(Interval(info['o']))
272 def __repr__(self):
273 return '<Date %s>'%self.__str__()
275 def local(self, offset):
276 """Return this date as yyyy-mm-dd.hh:mm:ss in a local time zone."""
277 t = (self.year, self.month, self.day, self.hour + offset, self.minute,
278 self.second, 0, 0, 0)
279 self.year, self.month, self.day, self.hour, self.minute, \
280 self.second, x, x, x = time.gmtime(calendar.timegm(t))
282 def get_tuple(self):
283 return (self.year, self.month, self.day, self.hour, self.minute,
284 self.second, 0, 0, 0)
286 def serialise(self):
287 return '%4d%02d%02d%02d%02d%02d'%(self.year, self.month,
288 self.day, self.hour, self.minute, self.second)
290 class Interval:
291 '''
292 Date intervals are specified using the suffixes "y", "m", and "d". The
293 suffix "w" (for "week") means 7 days. Time intervals are specified in
294 hh:mm:ss format (the seconds may be omitted, but the hours and minutes
295 may not).
297 "3y" means three years
298 "2y 1m" means two years and one month
299 "1m 25d" means one month and 25 days
300 "2w 3d" means two weeks and three days
301 "1d 2:50" means one day, two hours, and 50 minutes
302 "14:00" means 14 hours
303 "0:04:33" means four minutes and 33 seconds
305 Example usage:
306 >>> Interval(" 3w 1 d 2:00")
307 <Interval 22d 2:00>
308 >>> Date(". + 2d") + Interval("- 3w")
309 <Date 2000-06-07.00:34:02>
311 Intervals are added/subtracted in order of:
312 seconds, minutes, hours, years, months, days
314 Calculations involving monts (eg '+2m') have no effect on days - only
315 days (or over/underflow from hours/mins/secs) will do that, and
316 days-per-month and leap years are accounted for. Leap seconds are not.
318 The interval format 'syyyymmddHHMMSS' (sign, year, month, day, hour,
319 minute, second) is the serialisation format returned by the serialise()
320 method, and is accepted as an argument on instatiation.
322 TODO: more examples, showing the order of addition operation
323 '''
324 def __init__(self, spec, sign=1):
325 """Construct an interval given a specification."""
326 if type(spec) == type(''):
327 self.set(spec)
328 else:
329 if len(spec) == 7:
330 self.sign, self.year, self.month, self.day, self.hour, \
331 self.minute, self.second = spec
332 else:
333 # old, buggy spec form
334 self.sign = sign
335 self.year, self.month, self.day, self.hour, self.minute, \
336 self.second = spec
338 def __cmp__(self, other):
339 """Compare this interval to another interval."""
340 if other is None:
341 return 1
342 for attr in ('year', 'month', 'day', 'hour', 'minute', 'second'):
343 if not hasattr(other, attr):
344 return 1
345 r = cmp(getattr(self, attr), getattr(other, attr))
346 if r: return r
347 return 0
349 def __str__(self):
350 """Return this interval as a string."""
351 sign = {1:'+', -1:'-'}[self.sign]
352 l = [sign]
353 if self.year: l.append('%sy'%self.year)
354 if self.month: l.append('%sm'%self.month)
355 if self.day: l.append('%sd'%self.day)
356 if self.second:
357 l.append('%d:%02d:%02d'%(self.hour, self.minute, self.second))
358 elif self.hour or self.minute:
359 l.append('%d:%02d'%(self.hour, self.minute))
360 return ' '.join(l)
362 def __add__(self, other):
363 if isinstance(other, Date):
364 # the other is a Date - produce a Date
365 return Date(other.addInterval(self))
366 elif isinstance(other, Interval):
367 # add the other Interval to this one
368 a = self.get_tuple()
369 b = other.get_tuple()
370 if b[0] < 0:
371 i = Interval([x-y for x,y in zip(a[1:],b[1:])])
372 else:
373 i = Interval([x+y for x,y in zip(a[1:],b[1:])])
374 return i
375 # nope, no idea what to do with this other...
376 raise TypeError, "Can't add %r"%other
378 def set(self, spec, interval_re=re.compile('''
379 \s*(?P<s>[-+])? # + or -
380 \s*((?P<y>\d+\s*)y)? # year
381 \s*((?P<m>\d+\s*)m)? # month
382 \s*((?P<w>\d+\s*)w)? # week
383 \s*((?P<d>\d+\s*)d)? # day
384 \s*(((?P<H>\d+):(?P<M>\d+))?(:(?P<S>\d+))?)? # time
385 \s*''', re.VERBOSE), serialised_re=re.compile('''
386 (?P<s>[+-])?1?(?P<y>([ ]{3}\d|\d{4}))(?P<m>\d{2})(?P<d>\d{2})
387 (?P<H>\d{2})(?P<M>\d{2})(?P<S>\d{2})''', re.VERBOSE)):
388 ''' set the date to the value in spec
389 '''
390 self.year = self.month = self.week = self.day = self.hour = \
391 self.minute = self.second = 0
392 self.sign = 1
393 m = serialised_re.match(spec)
394 if not m:
395 m = interval_re.match(spec)
396 if not m:
397 raise ValueError, _('Not an interval spec: [+-] [#y] [#m] [#w] '
398 '[#d] [[[H]H:MM]:SS]')
400 info = m.groupdict()
401 for group, attr in {'y':'year', 'm':'month', 'w':'week', 'd':'day',
402 'H':'hour', 'M':'minute', 'S':'second'}.items():
403 if info.get(group, None) is not None:
404 setattr(self, attr, int(info[group]))
406 if self.week:
407 self.day = self.day + self.week*7
409 if info['s'] is not None:
410 self.sign = {'+':1, '-':-1}[info['s']]
412 def __repr__(self):
413 return '<Interval %s>'%self.__str__()
415 def pretty(self):
416 ''' print up the date date using one of these nice formats..
417 '''
418 if self.year:
419 if self.year == 1:
420 return _('1 year')
421 else:
422 return _('%(number)s years')%{'number': self.year}
423 elif self.month or self.day > 13:
424 days = (self.month * 30) + self.day
425 if days > 28:
426 if int(days/30) > 1:
427 s = _('%(number)s months')%{'number': int(days/30)}
428 else:
429 s = _('1 month')
430 else:
431 s = _('%(number)s weeks')%{'number': int(days/7)}
432 elif self.day > 7:
433 s = _('1 week')
434 elif self.day > 1:
435 s = _('%(number)s days')%{'number': self.day}
436 elif self.day == 1 or self.hour > 12:
437 if self.sign > 0:
438 return _('tomorrow')
439 else:
440 return _('yesterday')
441 elif self.hour > 1:
442 s = _('%(number)s hours')%{'number': self.hour}
443 elif self.hour == 1:
444 if self.minute < 15:
445 s = _('an hour')
446 elif self.minute/15 == 2:
447 s = _('1 1/2 hours')
448 else:
449 s = _('1 %(number)s/4 hours')%{'number': self.minute/15}
450 elif self.minute < 1:
451 if self.sign > 0:
452 return _('in a moment')
453 else:
454 return _('just now')
455 elif self.minute == 1:
456 s = _('1 minute')
457 elif self.minute < 15:
458 s = _('%(number)s minutes')%{'number': self.minute}
459 elif int(self.minute/15) == 2:
460 s = _('1/2 an hour')
461 else:
462 s = _('%(number)s/4 hour')%{'number': int(self.minute/15)}
463 return s
465 def get_tuple(self):
466 return (self.sign, self.year, self.month, self.day, self.hour,
467 self.minute, self.second)
469 def serialise(self):
470 sign = self.sign > 0 and '+' or '-'
471 return '%s%04d%02d%02d%02d%02d%02d'%(sign, self.year, self.month,
472 self.day, self.hour, self.minute, self.second)
475 def test():
476 intervals = (" 3w 1 d 2:00", " + 2d", "3w")
477 for interval in intervals:
478 print '>>> Interval("%s")'%interval
479 print `Interval(interval)`
481 dates = (".", "2000-06-25.19:34:02", ". + 2d", "1997-04-17", "01-25",
482 "08-13.22:13", "14:25")
483 for date in dates:
484 print '>>> Date("%s")'%date
485 print `Date(date)`
487 sums = ((". + 2d", "3w"), (".", " 3w 1 d 2:00"))
488 for date, interval in sums:
489 print '>>> Date("%s") + Interval("%s")'%(date, interval)
490 print `Date(date) + Interval(interval)`
492 if __name__ == '__main__':
493 test()
495 # vim: set filetype=python ts=4 sw=4 et si