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 1.28 2002-09-10 12:44:42 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):
210 ''' print up the date date using a pretty format...
211 '''
212 str = time.strftime('%d %B %Y', (self.year, self.month,
213 self.day, self.hour, self.minute, self.second, 0, 0, 0))
214 if str[0] == '0': return ' ' + str[1:]
215 return str
217 def set(self, spec, offset=0, date_re=re.compile(r'''
218 (((?P<y>\d\d\d\d)-)?((?P<m>\d\d?)-(?P<d>\d\d?))?)? # yyyy-mm-dd
219 (?P<n>\.)? # .
220 (((?P<H>\d?\d):(?P<M>\d\d))?(:(?P<S>\d\d))?)? # hh:mm:ss
221 (?P<o>.+)? # offset
222 ''', re.VERBOSE), serialised_re=re.compile('''
223 (?P<y>\d{4})(?P<m>\d{2})(?P<d>\d{2}) # yyyymmdd
224 (?P<H>\d{2})(?P<M>\d{2})(?P<S>\d{2}) # HHMMSS
225 ''', re.VERBOSE)):
226 ''' set the date to the value in spec
227 '''
228 m = serialised_re.match(spec)
229 if not m:
230 m = date_re.match(spec)
231 if not m:
232 raise ValueError, _('Not a date spec: [[yyyy-]mm-dd].'
233 '[[h]h:mm[:ss]][offset]')
235 info = m.groupdict()
237 # get the current date/time using the offset
238 y,m,d,H,M,S,x,x,x = time.gmtime(time.time())
240 # override year, month, day parts
241 if info['m'] is not None and info['d'] is not None:
242 m = int(info['m'])
243 d = int(info['d'])
244 if info['y'] is not None: y = int(info['y'])
245 H = M = S = 0
247 # override hour, minute, second parts
248 if info['H'] is not None and info['M'] is not None:
249 H = int(info['H']) - offset
250 M = int(info['M'])
251 S = 0
252 if info['S'] is not None: S = int(info['S'])
254 # now handle the adjustment of hour
255 ts = calendar.timegm((y,m,d,H,M,S,0,0,0))
256 self.year, self.month, self.day, self.hour, self.minute, \
257 self.second, x, x, x = time.gmtime(ts)
259 if info.get('o', None):
260 self.applyInterval(Interval(info['o']))
262 def __repr__(self):
263 return '<Date %s>'%self.__str__()
265 def local(self, offset):
266 """Return this date as yyyy-mm-dd.hh:mm:ss in a local time zone."""
267 t = (self.year, self.month, self.day, self.hour + offset, self.minute,
268 self.second, 0, 0, 0)
269 self.year, self.month, self.day, self.hour, self.minute, \
270 self.second, x, x, x = time.gmtime(calendar.timegm(t))
272 def get_tuple(self):
273 return (self.year, self.month, self.day, self.hour, self.minute,
274 self.second, 0, 0, 0)
276 def serialise(self):
277 return '%4d%02d%02d%02d%02d%02d'%(self.year, self.month,
278 self.day, self.hour, self.minute, self.second)
280 class Interval:
281 '''
282 Date intervals are specified using the suffixes "y", "m", and "d". The
283 suffix "w" (for "week") means 7 days. Time intervals are specified in
284 hh:mm:ss format (the seconds may be omitted, but the hours and minutes
285 may not).
287 "3y" means three years
288 "2y 1m" means two years and one month
289 "1m 25d" means one month and 25 days
290 "2w 3d" means two weeks and three days
291 "1d 2:50" means one day, two hours, and 50 minutes
292 "14:00" means 14 hours
293 "0:04:33" means four minutes and 33 seconds
295 Example usage:
296 >>> Interval(" 3w 1 d 2:00")
297 <Interval 22d 2:00>
298 >>> Date(". + 2d") + Interval("- 3w")
299 <Date 2000-06-07.00:34:02>
301 Intervals are added/subtracted in order of:
302 seconds, minutes, hours, years, months, days
304 Calculations involving monts (eg '+2m') have no effect on days - only
305 days (or over/underflow from hours/mins/secs) will do that, and
306 days-per-month and leap years are accounted for. Leap seconds are not.
308 The interval format 'syyyymmddHHMMSS' (sign, year, month, day, hour,
309 minute, second) is the serialisation format returned by the serialise()
310 method, and is accepted as an argument on instatiation.
312 TODO: more examples, showing the order of addition operation
313 '''
314 def __init__(self, spec, sign=1):
315 """Construct an interval given a specification."""
316 if type(spec) == type(''):
317 self.set(spec)
318 else:
319 if len(spec) == 7:
320 self.sign, self.year, self.month, self.day, self.hour, \
321 self.minute, self.second = spec
322 else:
323 # old, buggy spec form
324 self.sign = sign
325 self.year, self.month, self.day, self.hour, self.minute, \
326 self.second = spec
328 def __cmp__(self, other):
329 """Compare this interval to another interval."""
330 if other is None:
331 return 1
332 for attr in ('year', 'month', 'day', 'hour', 'minute', 'second'):
333 if not hasattr(other, attr):
334 return 1
335 r = cmp(getattr(self, attr), getattr(other, attr))
336 if r: return r
337 return 0
339 def __str__(self):
340 """Return this interval as a string."""
341 sign = {1:'+', -1:'-'}[self.sign]
342 l = [sign]
343 if self.year: l.append('%sy'%self.year)
344 if self.month: l.append('%sm'%self.month)
345 if self.day: l.append('%sd'%self.day)
346 if self.second:
347 l.append('%d:%02d:%02d'%(self.hour, self.minute, self.second))
348 elif self.hour or self.minute:
349 l.append('%d:%02d'%(self.hour, self.minute))
350 return ' '.join(l)
352 def set(self, spec, interval_re=re.compile('''
353 \s*(?P<s>[-+])? # + or -
354 \s*((?P<y>\d+\s*)y)? # year
355 \s*((?P<m>\d+\s*)m)? # month
356 \s*((?P<w>\d+\s*)w)? # week
357 \s*((?P<d>\d+\s*)d)? # day
358 \s*(((?P<H>\d+):(?P<M>\d+))?(:(?P<S>\d+))?)? # time
359 \s*''', re.VERBOSE), serialised_re=re.compile('''
360 (?P<s>[+-])(?P<y>\d{4})(?P<m>\d{2})(?P<d>\d{2})
361 (?P<H>\d{2})(?P<M>\d{2})(?P<S>\d{2})''', re.VERBOSE)):
362 ''' set the date to the value in spec
363 '''
364 self.year = self.month = self.week = self.day = self.hour = \
365 self.minute = self.second = 0
366 self.sign = 1
367 m = serialised_re.match(spec)
368 if not m:
369 m = interval_re.match(spec)
370 if not m:
371 raise ValueError, _('Not an interval spec: [+-] [#y] [#m] [#w] '
372 '[#d] [[[H]H:MM]:SS]')
374 info = m.groupdict()
375 for group, attr in {'y':'year', 'm':'month', 'w':'week', 'd':'day',
376 'H':'hour', 'M':'minute', 'S':'second'}.items():
377 if info.get(group, None) is not None:
378 setattr(self, attr, int(info[group]))
380 if self.week:
381 self.day = self.day + self.week*7
383 if info['s'] is not None:
384 self.sign = {'+':1, '-':-1}[info['s']]
386 def __repr__(self):
387 return '<Interval %s>'%self.__str__()
389 def pretty(self):
390 ''' print up the date date using one of these nice formats..
391 '''
392 if self.year:
393 if self.year == 1:
394 return _('1 year')
395 else:
396 return _('%(number)s years')%{'number': self.year}
397 elif self.month or self.day > 13:
398 days = (self.month * 30) + self.day
399 if days > 28:
400 if int(days/30) > 1:
401 s = _('%(number)s months')%{'number': int(days/30)}
402 else:
403 s = _('1 month')
404 else:
405 s = _('%(number)s weeks')%{'number': int(days/7)}
406 elif self.day > 7:
407 s = _('1 week')
408 elif self.day > 1:
409 s = _('%(number)s days')%{'number': self.day}
410 elif self.day == 1 or self.hour > 12:
411 if self.sign > 0:
412 return _('tomorrow')
413 else:
414 return _('yesterday')
415 elif self.hour > 1:
416 s = _('%(number)s hours')%{'number': self.hour}
417 elif self.hour == 1:
418 if self.minute < 15:
419 s = _('an hour')
420 elif self.minute/15 == 2:
421 s = _('1 1/2 hours')
422 else:
423 s = _('1 %(number)s/4 hours')%{'number': self.minute/15}
424 elif self.minute < 1:
425 if self.sign > 0:
426 return _('in a moment')
427 else:
428 return _('just now')
429 elif self.minute == 1:
430 s = _('1 minute')
431 elif self.minute < 15:
432 s = _('%(number)s minutes')%{'number': self.minute}
433 elif int(self.minute/15) == 2:
434 s = _('1/2 an hour')
435 else:
436 s = _('%(number)s/4 hour')%{'number': int(self.minute/15)}
437 return s
439 def get_tuple(self):
440 return (self.sign, self.year, self.month, self.day, self.hour,
441 self.minute, self.second)
443 def serialise(self):
444 return '%s%4d%02d%02d%02d%02d%02d'%(self.sign, self.year, self.month,
445 self.day, self.hour, self.minute, self.second)
448 def test():
449 intervals = (" 3w 1 d 2:00", " + 2d", "3w")
450 for interval in intervals:
451 print '>>> Interval("%s")'%interval
452 print `Interval(interval)`
454 dates = (".", "2000-06-25.19:34:02", ". + 2d", "1997-04-17", "01-25",
455 "08-13.22:13", "14:25")
456 for date in dates:
457 print '>>> Date("%s")'%date
458 print `Date(date)`
460 sums = ((". + 2d", "3w"), (".", " 3w 1 d 2:00"))
461 for date, interval in sums:
462 print '>>> Date("%s") + Interval("%s")'%(date, interval)
463 print `Date(date) + Interval(interval)`
465 if __name__ == '__main__':
466 test()
468 # vim: set filetype=python ts=4 sw=4 et si