| paul@152 | 1 | #!/usr/bin/env python |
| paul@152 | 2 | |
| paul@152 | 3 | """ |
| paul@152 | 4 | Date processing functions. |
| paul@152 | 5 | |
| paul@152 | 6 | Copyright (C) 2014, 2015 Paul Boddie <paul@boddie.org.uk> |
| paul@152 | 7 | |
| paul@152 | 8 | This program is free software; you can redistribute it and/or modify it under |
| paul@152 | 9 | the terms of the GNU General Public License as published by the Free Software |
| paul@152 | 10 | Foundation; either version 3 of the License, or (at your option) any later |
| paul@152 | 11 | version. |
| paul@152 | 12 | |
| paul@152 | 13 | This program is distributed in the hope that it will be useful, but WITHOUT |
| paul@152 | 14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| paul@152 | 15 | FOR A PARTICULAR PURPOSE. See the GNU General Public License for more |
| paul@152 | 16 | details. |
| paul@152 | 17 | |
| paul@152 | 18 | You should have received a copy of the GNU General Public License along with |
| paul@152 | 19 | this program. If not, see <http://www.gnu.org/licenses/>. |
| paul@152 | 20 | """ |
| paul@152 | 21 | |
| paul@152 | 22 | from datetime import date, datetime |
| paul@152 | 23 | from pytz import timezone, UnknownTimeZoneError |
| paul@152 | 24 | import re |
| paul@152 | 25 | |
| paul@152 | 26 | # iCalendar date and datetime parsing (from DateSupport in MoinSupport). |
| paul@152 | 27 | |
| paul@152 | 28 | date_icalendar_regexp_str = ur'(?P<year>[0-9]{4})(?P<month>[0-9]{2})(?P<day>[0-9]{2})' |
| paul@152 | 29 | datetime_icalendar_regexp_str = date_icalendar_regexp_str + \ |
| paul@152 | 30 | ur'(?:' \ |
| paul@152 | 31 | ur'T(?P<hour>[0-2][0-9])(?P<minute>[0-5][0-9])(?P<second>[0-6][0-9])' \ |
| paul@152 | 32 | ur'(?P<utc>Z)?' \ |
| paul@152 | 33 | ur')?' |
| paul@152 | 34 | |
| paul@152 | 35 | match_date_icalendar = re.compile(date_icalendar_regexp_str, re.UNICODE).match |
| paul@152 | 36 | match_datetime_icalendar = re.compile(datetime_icalendar_regexp_str, re.UNICODE).match |
| paul@152 | 37 | |
| paul@152 | 38 | def to_utc_datetime(dt): |
| paul@152 | 39 | if not dt: |
| paul@152 | 40 | return None |
| paul@152 | 41 | elif isinstance(dt, datetime): |
| paul@152 | 42 | return dt.astimezone(timezone("UTC")) |
| paul@152 | 43 | else: |
| paul@152 | 44 | return dt |
| paul@152 | 45 | |
| paul@152 | 46 | def to_timezone(dt, name): |
| paul@152 | 47 | try: |
| paul@152 | 48 | tz = name and timezone(name) or None |
| paul@152 | 49 | except UnknownTimeZoneError: |
| paul@152 | 50 | tz = None |
| paul@152 | 51 | if tz is not None: |
| paul@152 | 52 | if not dt.tzinfo: |
| paul@152 | 53 | return tz.localize(dt) |
| paul@152 | 54 | else: |
| paul@152 | 55 | return dt.astimezone(tz) |
| paul@152 | 56 | else: |
| paul@152 | 57 | return dt |
| paul@152 | 58 | |
| paul@152 | 59 | def format_datetime(dt): |
| paul@152 | 60 | if not dt: |
| paul@152 | 61 | return None |
| paul@152 | 62 | elif isinstance(dt, datetime): |
| paul@152 | 63 | if dt.tzname() == "UTC": |
| paul@152 | 64 | return dt.strftime("%Y%m%dT%H%M%SZ") |
| paul@152 | 65 | else: |
| paul@152 | 66 | return dt.strftime("%Y%m%dT%H%M%S") |
| paul@152 | 67 | else: |
| paul@152 | 68 | return dt.strftime("%Y%m%d") |
| paul@152 | 69 | |
| paul@152 | 70 | def get_datetime(value, attr=None): |
| paul@152 | 71 | |
| paul@152 | 72 | """ |
| paul@152 | 73 | Return a datetime object from the given 'value' in iCalendar format, using |
| paul@152 | 74 | the 'attr' mapping (if specified) to control the conversion. |
| paul@152 | 75 | """ |
| paul@152 | 76 | |
| paul@152 | 77 | if not attr or attr.get("VALUE") in (None, "DATE-TIME"): |
| paul@152 | 78 | m = match_datetime_icalendar(value) |
| paul@152 | 79 | if m: |
| paul@152 | 80 | dt = datetime( |
| paul@152 | 81 | int(m.group("year")), int(m.group("month")), int(m.group("day")), |
| paul@152 | 82 | int(m.group("hour")), int(m.group("minute")), int(m.group("second")) |
| paul@152 | 83 | ) |
| paul@152 | 84 | |
| paul@152 | 85 | # Impose the indicated timezone. |
| paul@152 | 86 | # NOTE: This needs an ambiguity policy for DST changes. |
| paul@152 | 87 | |
| paul@152 | 88 | return to_timezone(dt, m.group("utc") and "UTC" or attr and attr.get("TZID") or None) |
| paul@152 | 89 | |
| paul@152 | 90 | if not attr or attr.get("VALUE") == "DATE": |
| paul@152 | 91 | m = match_date_icalendar(value) |
| paul@152 | 92 | if m: |
| paul@152 | 93 | return date( |
| paul@152 | 94 | int(m.group("year")), int(m.group("month")), int(m.group("day")) |
| paul@152 | 95 | ) |
| paul@152 | 96 | return None |
| paul@152 | 97 | |
| paul@152 | 98 | def get_start_of_day(dt): |
| paul@152 | 99 | return datetime(dt.year, dt.month, dt.day, 0, 0, tzinfo=dt.tzinfo) |
| paul@152 | 100 | |
| paul@152 | 101 | # vim: tabstop=4 expandtab shiftwidth=4 |
