1
2
3 """
4 isodate.py
5
6 Functions for manipulating a subset of ISO8601 date, as specified by
7 <http://www.w3.org/TR/NOTE-datetime>
8
9 Exposes:
10 - parse(s)
11 s being a conforming (regular or unicode) string. Raises ValueError for
12 invalid strings. Returns a float (representing seconds from the epoch;
13 see the time module).
14
15 - parse_datetime(s) # if datetime module is available
16 s being a conforming (regular or unicode) string. Raises ValueError for
17 invalid strings. Returns a datetime instance.
18
19 - asString(i)
20 i being an integer or float. Returns a conforming string.
21
22 TODO:
23 - Precision? it would be nice to have an interface that tells us how
24 precise a datestring is, so that we don't make assumptions about it;
25 e.g., 2001 != 2001-01-01T00:00:00Z.
26
27 Thanks to Andrew Dalke for datetime support.
28 """
29
30 __license__ = """
31 Copyright (c) 2002-2005 Mark Nottingham <mnot@pobox.com>
32
33 Permission is hereby granted, free of charge, to any person obtaining a copy
34 of this software and associated documentation files (the "Software"), to deal
35 in the Software without restriction, including without limitation the rights
36 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
37 copies of the Software, and to permit persons to whom the Software is
38 furnished to do so, subject to the following conditions:
39
40 The above copyright notice and this permission notice shall be included in all
41 copies or substantial portions of the Software.
42
43 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
44 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
45 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
46 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
47 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
48 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
49 SOFTWARE.
50
51 Note: datetime support added by Andrew Dalke <dalke@dalkescientific.com>.
52 All copyrightable changes by Andrew Dalke are released into the public domain.
53 No copyright protection is asserted.
54 """
55
56
57 import sys, time, re, operator
58 from types import IntType, FloatType
59 from calendar import timegm
60
61 try:
62 import datetime
63 except ImportError:
64 _has_datetime = 0
65 else:
66 _has_datetime = 1
67
68
69 __version__ = "0.7"
70
71 date_parser = re.compile(r"""^
72 (?P<year>\d{4,4})
73 (?:
74 -
75 (?P<month>\d{1,2})
76 (?:
77 -
78 (?P<day>\d{1,2})
79 (?:
80 T
81 (?P<hour>\d{1,2})
82 :
83 (?P<minute>\d{1,2})
84 (?:
85 :
86 (?P<second>\d{1,2})
87 (?:
88 \.
89 (?P<dec_second>\d+)?
90 )?
91 )?
92 (?:
93 Z
94 |
95 (?:
96 (?P<tz_sign>[+-])
97 (?P<tz_hour>\d{1,2})
98 :
99 (?P<tz_min>\d{2,2})
100 )
101 )
102 )?
103 )?
104 )?
105 $""", re.VERBOSE)
106
107
109 """ parse a string and return seconds since the epoch. """
110 assert isinstance(s, basestring)
111 r = date_parser.search(s)
112 try:
113 a = r.groupdict('0')
114 except:
115 raise ValueError, 'invalid date string format'
116 d = timegm(( int(a['year']),
117 int(a['month']) or 1,
118 int(a['day']) or 1,
119 int(a['hour']),
120 int(a['minute']),
121 int(a['second']),
122 0,
123 0,
124 0
125 ))
126 return d - int("%s%s" % (
127 a.get('tz_sign', '+'),
128 ( int(a.get('tz_hour', 0)) * 60 * 60 ) + \
129 ( int(a.get('tz_min', 0)) * 60 ))
130 )
131
132 if _has_datetime:
134 """ parse a string and return a datetime object. """
135 assert isinstance(s, basestring)
136 r = date_parser.search(s)
137 try:
138 a = r.groupdict('0')
139 except:
140 raise ValueError, 'invalid date string format'
141
142 dt = datetime.datetime(int(a['year']),
143 int(a['month']) or 1,
144 int(a['day']) or 1,
145
146 int(a['hour']),
147 int(a['minute']),
148 int(a['second']),
149
150 int(a['dec_second'])*100000,
151 )
152 tz_hours_offset = int(a['tz_hour'])
153 tz_mins_offset = int(a['tz_min'])
154 if a.get('tz_sign', '+') == "-":
155 return dt + datetime.timedelta(hours = tz_hours_offset,
156 minutes = tz_mins_offset)
157 else:
158 return dt - datetime.timedelta(hours = tz_hours_offset,
159 minutes = tz_mins_offset)
160
162 """ given seconds since the epoch, return a dateTime string. """
163 assert type(i) in [IntType, FloatType]
164 year, month, day, hour, minute, second, wday, jday, dst = time.gmtime(i)
165 o = str(year)
166 if (month, day, hour, minute, second) == (1, 1, 0, 0, 0): return o
167 o = o + '-%2.2d' % month
168 if (day, hour, minute, second) == (1, 0, 0, 0): return o
169 o = o + '-%2.2d' % day
170 if (hour, minute, second) == (0, 0, 0): return o
171 o = o + 'T%2.2d:%2.2d' % (hour, minute)
172 if second != 0:
173 o = o + ':%2.2d' % second
174 o = o + 'Z'
175 return o
176
177
179 for iso in ("1997-07-16T19:20+01:00",
180 "2001-12-15T22:43:46Z",
181 "2004-09-26T21:10:15Z",
182 "2004",
183 "2005-04",
184 "2005-04-30",
185 "2004-09-26T21:10:15.1Z",
186 "2004-09-26T21:10:15.1+05:00",
187 "2004-09-26T21:10:15.1-05:00",
188 ):
189 timestamp = parse(iso)
190 dt1 = datetime.datetime.utcfromtimestamp(timestamp)
191 dt2 = parse_datetime(iso)
192 if (dt1 != dt2 and
193 dt1 != dt2.replace(microsecond=0)):
194 raise AssertionError("Different: %r != %r" %
195 (dt1, dt2))
196
197 if __name__ == "__main__":
198 print parse("1997-07-16T19:20+01:00")
199 print parse("2001-12-15T22:43:46Z")
200 print parse("2004-09-26T21:10:15Z")
201 if _has_datetime:
202 _cross_test()
203 print parse_datetime("1997-07-16T19:20+01:00")
204 print parse_datetime("2001-12-15T22:43:46Z")
205 print parse_datetime("2004-09-26T21:10:15Z")
206