"""Definitions and behavior for iCalendar, also known as vCalendar 2.0""" from __future__ import print_function import codecs import datetime import logging import random # for generating a UID import socket import string from dateutil import rrule, tz import six try: import pytz except ImportError: class Pytz: """fake pytz module (pytz is not required)""" class AmbiguousTimeError(Exception): """pytz error for ambiguous times during transition daylight->standard""" class NonExistentTimeError(Exception): """pytz error for non-existent times during transition standard->daylight""" pytz = Pytz # keeps quantifiedcode happy from . import behavior from .base import (VObjectError, NativeError, ValidateError, ParseError, Component, ContentLine, logger, registerBehavior, backslashEscape, foldOneLine, str_) # ------------------------------- Constants ------------------------------------ DATENAMES = ("rdate", "exdate") RULENAMES = ("exrule", "rrule") DATESANDRULES = ("exrule", "rrule", "rdate", "exdate") PRODID = u"-//PYVOBJECT//NONSGML Version 1//EN" WEEKDAYS = "MO", "TU", "WE", "TH", "FR", "SA", "SU" FREQUENCIES = ('YEARLY', 'MONTHLY', 'WEEKLY', 'DAILY', 'HOURLY', 'MINUTELY', 'SECONDLY') zeroDelta = datetime.timedelta(0) twoHours = datetime.timedelta(hours=2) # ---------------------------- TZID registry ----------------------------------- __tzidMap={} def toUnicode(s): """ Take a string or unicode, turn it into unicode, decoding as utf-8 """ if isinstance(s, six.binary_type): s = s.decode('utf-8') return s def registerTzid(tzid, tzinfo): """ Register a tzid -> tzinfo mapping. """ __tzidMap[toUnicode(tzid)]=tzinfo def getTzid(tzid, smart=True): """ Return the tzid if it exists, or None. """ tz = __tzidMap.get(toUnicode(tzid), None) if smart and tzid and not tz: try: from pytz import timezone, UnknownTimeZoneError try: tz = timezone(tzid) registerTzid(toUnicode(tzid), tz) except UnknownTimeZoneError as e: logging.error(e) except ImportError as e: logging.error(e) return tz utc = tz.tzutc() registerTzid("UTC", utc) # -------------------- Helper subclasses --------------------------------------- class TimezoneComponent(Component): """ A VTIMEZONE object. VTIMEZONEs are parsed by tz.tzical, the resulting datetime.tzinfo subclass is stored in self.tzinfo, self.tzid stores the TZID associated with this timezone. @ivar name: The uppercased name of the object, in this case always 'VTIMEZONE'. @ivar tzinfo: A datetime.tzinfo subclass representing this timezone. @ivar tzid: The string used to refer to this timezone. """ def __init__(self, tzinfo=None, *args, **kwds): """ Accept an existing Component or a tzinfo class. """ super(TimezoneComponent, self).__init__(*args, **kwds) self.isNative=True # hack to make sure a behavior is assigned if self.behavior is None: self.behavior = VTimezone if tzinfo is not None: self.tzinfo = tzinfo if not hasattr(self, 'name') or self.name == '': self.name = 'VTIMEZONE' self.useBegin = True @classmethod def registerTzinfo(obj, tzinfo): """ Register tzinfo if it's not already registered, return its tzid. """ tzid = obj.pickTzid(tzinfo) if tzid and not getTzid(tzid, False): registerTzid(tzid, tzinfo) return tzid def gettzinfo(self): # workaround for dateutil failing to parse some experimental properties good_lines = ('rdate', 'rrule', 'dtstart', 'tzname', 'tzoffsetfrom', 'tzoffsetto', 'tzid') # serialize encodes as utf-8, cStringIO will leave utf-8 alone buffer = six.StringIO() # allow empty VTIMEZONEs if len(self.contents) == 0: return None def customSerialize(obj): if isinstance(obj, Component): foldOneLine(buffer, u"BEGIN:" + obj.name) for child in obj.lines(): if child.name.lower() in good_lines: child.serialize(buffer, 75, validate=False) for comp in obj.components(): customSerialize(comp) foldOneLine(buffer, u"END:" + obj.name) customSerialize(self) buffer.seek(0) # tzical wants to read a stream return tz.tzical(buffer).get() def settzinfo(self, tzinfo, start=2000, end=2030): """ Create appropriate objects in self to represent tzinfo. Collapse DST transitions to rrules as much as possible. Assumptions: - DST <-> Standard transitions occur on the hour - never within a month of one another - twice or fewer times a year - never in the month of December - DST always moves offset exactly one hour later - tzinfo classes dst method always treats times that could be in either offset as being in the later regime """ def fromLastWeek(dt): """ How many weeks from the end of the month dt is, starting from 1. """ weekDelta = datetime.timedelta(weeks=1) n = 1 current = dt + weekDelta while current.month == dt.month: n += 1 current += weekDelta return n # lists of dictionaries defining rules which are no longer in effect completed = {'daylight' : [], 'standard' : []} # dictionary defining rules which are currently in effect working = {'daylight' : None, 'standard' : None} # rule may be based on nth week of the month or the nth from the last for year in range(start, end + 1): newyear = datetime.datetime(year, 1, 1) for transitionTo in 'daylight', 'standard': transition = getTransition(transitionTo, year, tzinfo) oldrule = working[transitionTo] if transition == newyear: # transitionTo is in effect for the whole year rule = {'end' : None, 'start' : newyear, 'month' : 1, 'weekday' : None, 'hour' : None, 'plus' : None, 'minus' : None, 'name' : tzinfo.tzname(newyear), 'offset' : tzinfo.utcoffset(newyear), 'offsetfrom' : tzinfo.utcoffset(newyear)} if oldrule is None: # transitionTo was not yet in effect working[transitionTo] = rule else: # transitionTo was already in effect if (oldrule['offset'] != tzinfo.utcoffset(newyear)): # old rule was different, it shouldn't continue oldrule['end'] = year - 1 completed[transitionTo].append(oldrule) working[transitionTo] = rule elif transition is None: # transitionTo is not in effect if oldrule is not None: # transitionTo used to be in effect oldrule['end'] = year - 1 completed[transitionTo].append(oldrule) working[transitionTo] = None else: # an offset transition was found try: old_offset = tzinfo.utcoffset(transition - twoHours) name = tzinfo.tzname(transition) offset = tzinfo.utcoffset(transition) except (pytz.AmbiguousTimeError, pytz.NonExistentTimeError): # guaranteed that tzinfo is a pytz timezone is_dst = (transitionTo == "daylight") old_offset = tzinfo.utcoffset(transition - twoHours, is_dst=is_dst) name = tzinfo.tzname(transition, is_dst=is_dst) offset = tzinfo.utcoffset(transition, is_dst=is_dst) rule = {'end' : None, # None, or an integer year 'start' : transition, # the datetime of transition 'month' : transition.month, 'weekday' : transition.weekday(), 'hour' : transition.hour, 'name' : name, 'plus' : int( (transition.day - 1)/ 7 + 1), # nth week of the month 'minus' : fromLastWeek(transition), # nth from last week 'offset' : offset, 'offsetfrom' : old_offset} if oldrule is None: working[transitionTo] = rule else: plusMatch = rule['plus'] == oldrule['plus'] minusMatch = rule['minus'] == oldrule['minus'] truth = plusMatch or minusMatch for key in 'month', 'weekday', 'hour', 'offset': truth = truth and rule[key] == oldrule[key] if truth: # the old rule is still true, limit to plus or minus if not plusMatch: oldrule['plus'] = None if not minusMatch: oldrule['minus'] = None else: # the new rule did not match the old oldrule['end'] = year - 1 completed[transitionTo].append(oldrule) working[transitionTo] = rule for transitionTo in 'daylight', 'standard': if working[transitionTo] is not None: completed[transitionTo].append(working[transitionTo]) self.tzid = [] self.daylight = [] self.standard = [] self.add('tzid').value = self.pickTzid(tzinfo, True) # old = None # unused? for transitionTo in 'daylight', 'standard': for rule in completed[transitionTo]: comp = self.add(transitionTo) dtstart = comp.add('dtstart') dtstart.value = rule['start'] if rule['name'] is not None: comp.add('tzname').value = rule['name'] line = comp.add('tzoffsetto') line.value = deltaToOffset(rule['offset']) line = comp.add('tzoffsetfrom') line.value = deltaToOffset(rule['offsetfrom']) if rule['plus'] is not None: num = rule['plus'] elif rule['minus'] is not None: num = -1 * rule['minus'] else: num = None if num is not None: dayString = ";BYDAY=" + str(num) + WEEKDAYS[rule['weekday']] else: dayString = "" if rule['end'] is not None: if rule['hour'] is None: # all year offset, with no rule endDate = datetime.datetime(rule['end'], 1, 1) else: weekday = rrule.weekday(rule['weekday'], num) du_rule = rrule.rrule(rrule.YEARLY, bymonth = rule['month'],byweekday = weekday, dtstart = datetime.datetime( rule['end'], 1, 1, rule['hour']) ) endDate = du_rule[0] endDate = endDate.replace(tzinfo = utc) - rule['offsetfrom'] endString = ";UNTIL="+ dateTimeToString(endDate) else: endString = '' new_rule = "FREQ=YEARLY{0!s};BYMONTH={1!s}{2!s}"\ .format(dayString, rule['month'], endString) comp.add('rrule').value = new_rule tzinfo = property(gettzinfo, settzinfo) # prevent Component's __setattr__ from overriding the tzinfo property normal_attributes = Component.normal_attributes + ['tzinfo'] @staticmethod def pickTzid(tzinfo, allowUTC=False): """ Given a tzinfo class, use known APIs to determine TZID, or use tzname. """ if tzinfo is None or (not allowUTC and tzinfo_eq(tzinfo, utc)): # If tzinfo is UTC, we don't need a TZID return None # try PyICU's tzid key if hasattr(tzinfo, 'tzid'): return toUnicode(tzinfo.tzid) # try pytz zone key if hasattr(tzinfo, 'zone'): return toUnicode(tzinfo.zone) # try tzical's tzid key elif hasattr(tzinfo, '_tzid'): return toUnicode(tzinfo._tzid) else: # return tzname for standard (non-DST) time notDST = datetime.timedelta(0) for month in range(1, 13): dt = datetime.datetime(2000, month, 1) if tzinfo.dst(dt) == notDST: return toUnicode(tzinfo.tzname(dt)) # there was no standard time in 2000! raise VObjectError("Unable to guess TZID for tzinfo {0!s}" .format(tzinfo)) def __str__(self): return "".format(getattr(self, 'tzid', 'No TZID')) def __repr__(self): return self.__str__() def prettyPrint(self, level, tabwidth): pre = ' ' * level * tabwidth print(pre, self.name) print(pre, "TZID:", self.tzid) print('') class RecurringComponent(Component): """ A vCalendar component like VEVENT or VTODO which may recur. Any recurring component can have one or multiple RRULE, RDATE, EXRULE, or EXDATE lines, and one or zero DTSTART lines. It can also have a variety of children that don't have any recurrence information. In the example below, note that dtstart is included in the rruleset. This is not the default behavior for dateutil's rrule implementation unless dtstart would already have been a member of the recurrence rule, and as a result, COUNT is wrong. This can be worked around when getting rruleset by adjusting count down by one if an rrule has a count and dtstart isn't in its result set, but by default, the rruleset property doesn't do this work around, to access it getrruleset must be called with addRDate set True. @ivar rruleset: A U{rruleset}. """ def __init__(self, *args, **kwds): super(RecurringComponent, self).__init__(*args, **kwds) self.isNative=True def getrruleset(self, addRDate = False): """ Get an rruleset created from self. If addRDate is True, add an RDATE for dtstart if it's not included in an RRULE, and count is decremented if it exists. Note that for rules which don't match DTSTART, DTSTART may not appear in list(rruleset), although it should. By default, an RDATE is not created in these cases, and count isn't updated, so dateutil may list a spurious occurrence. """ rruleset = None for name in DATESANDRULES: addfunc = None for line in self.contents.get(name, ()): # don't bother creating a rruleset unless there's a rule if rruleset is None: rruleset = rrule.rruleset() if addfunc is None: addfunc = getattr(rruleset, name) if name in DATENAMES: if type(line.value[0]) == datetime.datetime: map(addfunc, line.value) elif type(line.value[0]) == datetime.date: for dt in line.value: addfunc(datetime.datetime(dt.year, dt.month, dt.day)) else: # ignore RDATEs with PERIOD values for now pass elif name in RULENAMES: try: dtstart = self.dtstart.value except (AttributeError, KeyError): # Special for VTODO - try DUE property instead try: if self.name == "VTODO": dtstart = self.due.value else: # if there's no dtstart, just return None logging.error('failed to get dtstart with VTODO') return None except (AttributeError, KeyError): # if there's no due, just return None logging.error('failed to find DUE at all.') return None # a Ruby iCalendar library escapes semi-colons in rrules, # so also remove any backslashes value = str_(line.value).replace('\\', '') rule = rrule.rrulestr(value, dtstart=dtstart) until = rule._until if until is not None and isinstance(dtstart, datetime.datetime) and \ (until.tzinfo != dtstart.tzinfo): # dateutil converts the UNTIL date to a datetime, # check to see if the UNTIL parameter value was a date vals = dict(pair.split('=') for pair in line.value.upper().split(';')) if len(vals.get('UNTIL', '')) == 8: until = datetime.datetime.combine(until.date(), dtstart.time()) # While RFC2445 says UNTIL MUST be UTC, Chandler allows # floating recurring events, and uses floating UNTIL # values. Also, some odd floating UNTIL but timezoned # DTSTART values have shown up in the wild, so put # floating UNTIL values DTSTART's timezone if until.tzinfo is None: until = until.replace(tzinfo=dtstart.tzinfo) if dtstart.tzinfo is not None: until = until.astimezone(dtstart.tzinfo) # RFC2445 actually states that UNTIL must be a UTC # value. Whilst the changes above work OK, one problem # case is if DTSTART is floating but UNTIL is properly # specified as UTC (or with a TZID). In that case # dateutil will fail datetime comparisons. There is no # easy solution to this as there is no obvious timezone # (at this point) to do proper floating time offset # comparisons. The best we can do is treat the UNTIL # value as floating. This could mean incorrect # determination of the last instance. The better # solution here is to encourage clients to use COUNT # rather than UNTIL when DTSTART is floating. if dtstart.tzinfo is None: until = until.replace(tzinfo=None) rule._until = until # add the rrule or exrule to the rruleset addfunc(rule) if name == 'rrule' and addRDate: try: # dateutils does not work with all-day # (datetime.date) items so we need to convert to a # datetime.datetime (which is what dateutils # does internally) if not isinstance(dtstart, datetime.datetime): adddtstart = datetime.datetime.fromordinal(dtstart.toordinal()) else: adddtstart = dtstart if rruleset._rrule[-1][0] != adddtstart: rruleset.rdate(adddtstart) added = True else: added = False except IndexError: # it's conceivable that an rrule has 0 datetimes added = False if added and rruleset._rrule[-1]._count != None: rruleset._rrule[-1]._count -= 1 return rruleset def setrruleset(self, rruleset): # Get DTSTART from component (or DUE if no DTSTART in a VTODO) try: dtstart = self.dtstart.value except (AttributeError, KeyError): if self.name == "VTODO": dtstart = self.due.value else: raise isDate = datetime.date == type(dtstart) if isDate: dtstart = datetime.datetime(dtstart.year,dtstart.month, dtstart.day) untilSerialize = dateToString else: # make sure to convert time zones to UTC untilSerialize = lambda x: dateTimeToString(x, True) for name in DATESANDRULES: if name in self.contents: del self.contents[name] setlist = getattr(rruleset, '_' + name) if name in DATENAMES: setlist = list(setlist) # make a copy of the list if name == 'rdate' and dtstart in setlist: setlist.remove(dtstart) if isDate: setlist = [dt.date() for dt in setlist] if len(setlist) > 0: self.add(name).value = setlist elif name in RULENAMES: for rule in setlist: buf = six.StringIO() buf.write('FREQ=') buf.write(FREQUENCIES[rule._freq]) values = {} if rule._interval != 1: values['INTERVAL'] = [str(rule._interval)] if rule._wkst != 0: # wkst defaults to Monday values['WKST'] = [WEEKDAYS[rule._wkst]] if rule._bysetpos is not None: values['BYSETPOS'] = [str(i) for i in rule._bysetpos] if rule._count is not None: values['COUNT'] = [str(rule._count)] elif rule._until is not None: values['UNTIL'] = [untilSerialize(rule._until)] days = [] if (rule._byweekday is not None and ( rrule.WEEKLY != rule._freq or len(rule._byweekday) != 1 or rule._dtstart.weekday() != rule._byweekday[0])): # ignore byweekday if freq is WEEKLY and day correlates # with dtstart because it was automatically set by dateutil days.extend(WEEKDAYS[n] for n in rule._byweekday) if rule._bynweekday is not None: days.extend(n + WEEKDAYS[day] for day, n in rule._bynweekday) if len(days) > 0: values['BYDAY'] = days if rule._bymonthday is not None and len(rule._bymonthday) > 0: if not (rule._freq <= rrule.MONTHLY and len(rule._bymonthday) == 1 and rule._bymonthday[0] == rule._dtstart.day): # ignore bymonthday if it's generated by dateutil values['BYMONTHDAY'] = [str(n) for n in rule._bymonthday] if rule._bynmonthday is not None and len(rule._bynmonthday) > 0: values.setdefault('BYMONTHDAY', []).extend(str(n) for n in rule._bynmonthday) if rule._bymonth is not None and len(rule._bymonth) > 0: if (rule._byweekday is not None or len(rule._bynweekday or ()) > 0 or not (rule._freq == rrule.YEARLY and len(rule._bymonth) == 1 and rule._bymonth[0] == rule._dtstart.month)): # ignore bymonth if it's generated by dateutil values['BYMONTH'] = [str(n) for n in rule._bymonth] if rule._byyearday is not None: values['BYYEARDAY'] = [str(n) for n in rule._byyearday] if rule._byweekno is not None: values['BYWEEKNO'] = [str(n) for n in rule._byweekno] # byhour, byminute, bysecond are always ignored for now for key, paramvals in values.items(): buf.write(';') buf.write(key) buf.write('=') buf.write(','.join(paramvals)) self.add(name).value = buf.getvalue() rruleset = property(getrruleset, setrruleset) def __setattr__(self, name, value): """ For convenience, make self.contents directly accessible. """ if name == 'rruleset': self.setrruleset(value) else: super(RecurringComponent, self).__setattr__(name, value) class TextBehavior(behavior.Behavior): """ Provide backslash escape encoding/decoding for single valued properties. TextBehavior also deals with base64 encoding if the ENCODING parameter is explicitly set to BASE64. """ base64string = 'BASE64' # vCard uses B @classmethod def decode(cls, line): """ Remove backslash escaping from line.value. """ if line.encoded: encoding = getattr(line, 'encoding_param', None) if encoding and encoding.upper() == cls.base64string: line.value = codecs.decode(self.value.encode("utf-8"), "base64").decode(encoding) else: line.value = stringToTextValues(line.value)[0] line.encoded=False @classmethod def encode(cls, line): """ Backslash escape line.value. """ if not line.encoded: encoding = getattr(line, 'encoding_param', None) if encoding and encoding.upper() == cls.base64string: line.value = codecs.encode(self.value.encode(encoding), "base64").decode("utf-8") else: line.value = backslashEscape(str_(line.value)) line.encoded=True class VCalendarComponentBehavior(behavior.Behavior): defaultBehavior = TextBehavior isComponent = True class RecurringBehavior(VCalendarComponentBehavior): """ Parent Behavior for components which should be RecurringComponents. """ hasNative = True @staticmethod def transformToNative(obj): """ Turn a recurring Component into a RecurringComponent. """ if not obj.isNative: object.__setattr__(obj, '__class__', RecurringComponent) obj.isNative = True return obj @staticmethod def transformFromNative(obj): if obj.isNative: object.__setattr__(obj, '__class__', Component) obj.isNative = False return obj @staticmethod def generateImplicitParameters(obj): """ Generate a UID if one does not exist. This is just a dummy implementation, for now. """ if not hasattr(obj, 'uid'): rand = int(random.random() * 100000) now = datetime.datetime.now(utc) now = dateTimeToString(now) host = socket.gethostname() obj.add(ContentLine('UID', [], "{0} - {1}@{2}".format(now, rand, host))) class DateTimeBehavior(behavior.Behavior): """ Parent Behavior for ContentLines containing one DATE-TIME. """ hasNative = True @staticmethod def transformToNative(obj): """ Turn obj.value into a datetime. RFC2445 allows times without time zone information, "floating times" in some properties. Mostly, this isn't what you want, but when parsing a file, real floating times are noted by setting to 'TRUE' the X-VOBJ-FLOATINGTIME-ALLOWED parameter. """ if obj.isNative: return obj obj.isNative = True if obj.value == '': return obj obj.value=obj.value # we're cheating a little here, parseDtstart allows DATE obj.value=parseDtstart(obj) if obj.value.tzinfo is None: obj.params['X-VOBJ-FLOATINGTIME-ALLOWED'] = ['TRUE'] if obj.params.get('TZID'): # Keep a copy of the original TZID around obj.params['X-VOBJ-ORIGINAL-TZID'] = [obj.params['TZID']] del obj.params['TZID'] return obj @classmethod def transformFromNative(cls, obj): """ Replace the datetime in obj.value with an ISO 8601 string. """ if obj.isNative: obj.isNative = False tzid = TimezoneComponent.registerTzinfo(obj.value.tzinfo) obj.value = dateTimeToString(obj.value, cls.forceUTC) if not cls.forceUTC and tzid is not None: obj.tzid_param = tzid if obj.params.get('X-VOBJ-ORIGINAL-TZID'): if not hasattr(obj, 'tzid_param'): obj.tzid_param = obj.x_vobj_original_tzid_param del obj.params['X-VOBJ-ORIGINAL-TZID'] return obj class UTCDateTimeBehavior(DateTimeBehavior): """ A value which must be specified in UTC. """ forceUTC = True class DateOrDateTimeBehavior(behavior.Behavior): """ Parent Behavior for ContentLines containing one DATE or DATE-TIME. """ hasNative = True @staticmethod def transformToNative(obj): """ Turn obj.value into a date or datetime. """ if obj.isNative: return obj obj.isNative = True if obj.value == '': return obj obj.value=obj.value obj.value=parseDtstart(obj, allowSignatureMismatch=True) if getattr(obj, 'value_param', 'DATE-TIME').upper() == 'DATE-TIME': if hasattr(obj, 'tzid_param'): # Keep a copy of the original TZID around obj.params['X-VOBJ-ORIGINAL-TZID'] = [obj.tzid_param] del obj.tzid_param return obj @staticmethod def transformFromNative(obj): """ Replace the date or datetime in obj.value with an ISO 8601 string. """ if type(obj.value) == datetime.date: obj.isNative = False obj.value_param = 'DATE' obj.value = dateToString(obj.value) return obj else: return DateTimeBehavior.transformFromNative(obj) class MultiDateBehavior(behavior.Behavior): """ Parent Behavior for ContentLines containing one or more DATE, DATE-TIME, or PERIOD. """ hasNative = True @staticmethod def transformToNative(obj): """ Turn obj.value into a list of dates, datetimes, or (datetime, timedelta) tuples. """ if obj.isNative: return obj obj.isNative = True if obj.value == '': obj.value = [] return obj tzinfo = getTzid(getattr(obj, 'tzid_param', None)) valueParam = getattr(obj, 'value_param', "DATE-TIME").upper() valTexts = obj.value.split(",") if valueParam == "DATE": obj.value = [stringToDate(x) for x in valTexts] elif valueParam == "DATE-TIME": obj.value = [stringToDateTime(x, tzinfo) for x in valTexts] elif valueParam == "PERIOD": obj.value = [stringToPeriod(x, tzinfo) for x in valTexts] return obj @staticmethod def transformFromNative(obj): """ Replace the date, datetime or period tuples in obj.value with appropriate strings. """ if obj.value and type(obj.value[0]) == datetime.date: obj.isNative = False obj.value_param = 'DATE' obj.value = ','.join([dateToString(val) for val in obj.value]) return obj # Fixme: handle PERIOD case else: if obj.isNative: obj.isNative = False transformed = [] tzid = None for val in obj.value: if tzid is None and type(val) == datetime.datetime: tzid = TimezoneComponent.registerTzinfo(val.tzinfo) if tzid is not None: obj.tzid_param = tzid transformed.append(dateTimeToString(val)) obj.value = ','.join(transformed) return obj class MultiTextBehavior(behavior.Behavior): """ Provide backslash escape encoding/decoding of each of several values. After transformation, value is a list of strings. """ listSeparator = "," @classmethod def decode(cls, line): """ Remove backslash escaping from line.value, then split on commas. """ if line.encoded: line.value = stringToTextValues(line.value, listSeparator=cls.listSeparator) line.encoded=False @classmethod def encode(cls, line): """ Backslash escape line.value. """ if not line.encoded: line.value = cls.listSeparator.join(backslashEscape(val) for val in line.value) line.encoded=True class SemicolonMultiTextBehavior(MultiTextBehavior): listSeparator = ";" # ------------------------ Registered Behavior subclasses ---------------------- class VCalendar2_0(VCalendarComponentBehavior): """ vCalendar 2.0 behavior. With added VAVAILABILITY support. """ name = 'VCALENDAR' description = 'vCalendar 2.0, also known as iCalendar.' versionString = '2.0' sortFirst = ('version', 'calscale', 'method', 'prodid', 'vtimezone') knownChildren = {'CALSCALE': (0, 1, None), # min, max, behaviorRegistry id 'METHOD': (0, 1, None), 'VERSION': (0, 1, None), # required, but auto-generated 'PRODID': (1, 1, None), 'VTIMEZONE': (0, None, None), 'VEVENT': (0, None, None), 'VTODO': (0, None, None), 'VJOURNAL': (0, None, None), 'VFREEBUSY': (0, None, None), 'VAVAILABILITY': (0, None, None), } @classmethod def generateImplicitParameters(cls, obj): """ Create PRODID, VERSION, and VTIMEZONEs if needed. VTIMEZONEs will need to exist whenever TZID parameters exist or when datetimes with tzinfo exist. """ for comp in obj.components(): if comp.behavior is not None: comp.behavior.generateImplicitParameters(comp) if not hasattr(obj, 'prodid'): obj.add(ContentLine('PRODID', [], PRODID)) if not hasattr(obj, 'version'): obj.add(ContentLine('VERSION', [], cls.versionString)) tzidsUsed = {} def findTzids(obj, table): if isinstance(obj, ContentLine) and (obj.behavior is None or not obj.behavior.forceUTC): if getattr(obj, 'tzid_param', None): table[obj.tzid_param] = 1 else: if type(obj.value) == list: for item in obj.value: tzinfo = getattr(obj.value, 'tzinfo', None) tzid = TimezoneComponent.registerTzinfo(tzinfo) if tzid: table[tzid] = 1 else: tzinfo = getattr(obj.value, 'tzinfo', None) tzid = TimezoneComponent.registerTzinfo(tzinfo) if tzid: table[tzid] = 1 for child in obj.getChildren(): if obj.name != 'VTIMEZONE': findTzids(child, table) findTzids(obj, tzidsUsed) oldtzids = [toUnicode(x.tzid.value) for x in getattr(obj, 'vtimezone_list', [])] for tzid in tzidsUsed.keys(): tzid = toUnicode(tzid) if tzid != u'UTC' and tzid not in oldtzids: obj.add(TimezoneComponent(tzinfo=getTzid(tzid))) registerBehavior(VCalendar2_0) class VTimezone(VCalendarComponentBehavior): """ Timezone behavior. """ name = 'VTIMEZONE' hasNative = True description = 'A grouping of component properties that defines a time zone.' sortFirst = ('tzid', 'last-modified', 'tzurl', 'standard', 'daylight') knownChildren = {'TZID': (1, 1, None), # min, max, behaviorRegistry id 'LAST-MODIFIED':(0, 1, None), 'TZURL': (0, 1, None), 'STANDARD': (0, None, None), # NOTE: One of Standard or 'DAYLIGHT': (0, None, None) # Daylight must appear } @classmethod def validate(cls, obj, raiseException, *args): if not hasattr(obj, 'tzid') or obj.tzid.value is None: if raiseException: m = "VTIMEZONE components must contain a valid TZID" raise ValidateError(m) return False if 'standard' in obj.contents or 'daylight' in obj.contents: return super(VTimezone, cls).validate(obj, raiseException, *args) else: if raiseException: m = "VTIMEZONE components must contain a STANDARD or a DAYLIGHT\ component" raise ValidateError(m) return False @staticmethod def transformToNative(obj): if not obj.isNative: object.__setattr__(obj, '__class__', TimezoneComponent) obj.isNative = True obj.registerTzinfo(obj.tzinfo) return obj @staticmethod def transformFromNative(obj): return obj registerBehavior(VTimezone) class TZID(behavior.Behavior): """ Don't use TextBehavior for TZID. RFC2445 only allows TZID lines to be paramtext, so they shouldn't need any encoding or decoding. Unfortunately, some Microsoft products use commas in TZIDs which should NOT be treated as a multi-valued text property, nor do we want to escape them. Leaving them alone works for Microsoft's breakage, and doesn't affect compliant iCalendar streams. """ registerBehavior(TZID) class DaylightOrStandard(VCalendarComponentBehavior): hasNative = False knownChildren = {'DTSTART': (1, 1, None), # min, max, behaviorRegistry id 'RRULE': (0, 1, None)} registerBehavior(DaylightOrStandard, 'STANDARD') registerBehavior(DaylightOrStandard, 'DAYLIGHT') class VEvent(RecurringBehavior): """ Event behavior. """ name='VEVENT' sortFirst = ('uid', 'recurrence-id', 'dtstart', 'duration', 'dtend') description='A grouping of component properties, and possibly including \ "VALARM" calendar components, that represents a scheduled \ amount of time on a calendar.' knownChildren = {'DTSTART': (0, 1, None), # min, max, behaviorRegistry id 'CLASS': (0, 1, None), 'CREATED': (0, 1, None), 'DESCRIPTION': (0, 1, None), 'GEO': (0, 1, None), 'LAST-MODIFIED':(0, 1, None), 'LOCATION': (0, 1, None), 'ORGANIZER': (0, 1, None), 'PRIORITY': (0, 1, None), 'DTSTAMP': (0, 1, None), 'SEQUENCE': (0, 1, None), 'STATUS': (0, 1, None), 'SUMMARY': (0, 1, None), 'TRANSP': (0, 1, None), 'UID': (1, 1, None), 'URL': (0, 1, None), 'RECURRENCE-ID':(0, 1, None), 'DTEND': (0, 1, None), # NOTE: Only one of DtEnd or 'DURATION': (0, 1, None), # Duration can appear 'ATTACH': (0, None, None), 'ATTENDEE': (0, None, None), 'CATEGORIES': (0, None, None), 'COMMENT': (0, None, None), 'CONTACT': (0, None, None), 'EXDATE': (0, None, None), 'EXRULE': (0, None, None), 'REQUEST-STATUS': (0, None, None), 'RELATED-TO': (0, None, None), 'RESOURCES': (0, None, None), 'RDATE': (0, None, None), 'RRULE': (0, None, None), 'VALARM': (0, None, None) } @classmethod def validate(cls, obj, raiseException, *args): if 'dtend' in obj.contents and 'duration' in obj.contents: if raiseException: m = "VEVENT components cannot contain both DTEND and DURATION\ components" raise ValidateError(m) return False else: return super(VEvent, cls).validate(obj, raiseException, *args) registerBehavior(VEvent) class VTodo(RecurringBehavior): """ To-do behavior. """ name='VTODO' description='A grouping of component properties and possibly "VALARM" \ calendar components that represent an action-item or \ assignment.' knownChildren = {'DTSTART': (0, 1, None), # min, max, behaviorRegistry id 'CLASS': (0, 1, None), 'COMPLETED': (0, 1, None), 'CREATED': (0, 1, None), 'DESCRIPTION': (0, 1, None), 'GEO': (0, 1, None), 'LAST-MODIFIED':(0, 1, None), 'LOCATION': (0, 1, None), 'ORGANIZER': (0, 1, None), 'PERCENT': (0, 1, None), 'PRIORITY': (0, 1, None), 'DTSTAMP': (0, 1, None), 'SEQUENCE': (0, 1, None), 'STATUS': (0, 1, None), 'SUMMARY': (0, 1, None), 'UID': (0, 1, None), 'URL': (0, 1, None), 'RECURRENCE-ID':(0, 1, None), 'DUE': (0, 1, None), # NOTE: Only one of Due or 'DURATION': (0, 1, None), # Duration can appear 'ATTACH': (0, None, None), 'ATTENDEE': (0, None, None), 'CATEGORIES': (0, None, None), 'COMMENT': (0, None, None), 'CONTACT': (0, None, None), 'EXDATE': (0, None, None), 'EXRULE': (0, None, None), 'REQUEST-STATUS': (0, None, None), 'RELATED-TO': (0, None, None), 'RESOURCES': (0, None, None), 'RDATE': (0, None, None), 'RRULE': (0, None, None), 'VALARM': (0, None, None) } @classmethod def validate(cls, obj, raiseException, *args): if 'due' in obj.contents and 'duration' in obj.contents: if raiseException: m = "VTODO components cannot contain both DUE and DURATION\ components" raise ValidateError(m) return False else: return super(VTodo, cls).validate(obj, raiseException, *args) registerBehavior(VTodo) class VJournal(RecurringBehavior): """ Journal entry behavior. """ name='VJOURNAL' knownChildren = {'DTSTART': (0, 1, None), # min, max, behaviorRegistry id 'CLASS': (0, 1, None), 'CREATED': (0, 1, None), 'DESCRIPTION': (0, 1, None), 'LAST-MODIFIED':(0, 1, None), 'ORGANIZER': (0, 1, None), 'DTSTAMP': (0, 1, None), 'SEQUENCE': (0, 1, None), 'STATUS': (0, 1, None), 'SUMMARY': (0, 1, None), 'UID': (0, 1, None), 'URL': (0, 1, None), 'RECURRENCE-ID':(0, 1, None), 'ATTACH': (0, None, None), 'ATTENDEE': (0, None, None), 'CATEGORIES': (0, None, None), 'COMMENT': (0, None, None), 'CONTACT': (0, None, None), 'EXDATE': (0, None, None), 'EXRULE': (0, None, None), 'REQUEST-STATUS': (0, None, None), 'RELATED-TO': (0, None, None), 'RDATE': (0, None, None), 'RRULE': (0, None, None) } registerBehavior(VJournal) class VFreeBusy(VCalendarComponentBehavior): """ Free/busy state behavior. """ name='VFREEBUSY' description='A grouping of component properties that describe either a \ request for free/busy time, describe a response to a request \ for free/busy time or describe a published set of busy time.' sortFirst = ('uid', 'dtstart', 'duration', 'dtend') knownChildren = {'DTSTART': (0, 1, None), # min, max, behaviorRegistry id 'CONTACT': (0, 1, None), 'DTEND': (0, 1, None), 'DURATION': (0, 1, None), 'ORGANIZER': (0, 1, None), 'DTSTAMP': (0, 1, None), 'UID': (0, 1, None), 'URL': (0, 1, None), 'ATTENDEE': (0, None, None), 'COMMENT': (0, None, None), 'FREEBUSY': (0, None, None), 'REQUEST-STATUS': (0, None, None) } registerBehavior(VFreeBusy) class VAlarm(VCalendarComponentBehavior): """ Alarm behavior. """ name='VALARM' description='Alarms describe when and how to provide alerts about events \ and to-dos.' knownChildren = {'ACTION': (1, 1, None), # min, max, behaviorRegistry id 'TRIGGER': (1, 1, None), 'DURATION': (0, 1, None), 'REPEAT': (0, 1, None), 'DESCRIPTION': (0, 1, None) } @staticmethod def generateImplicitParameters(obj): """ Create default ACTION and TRIGGER if they're not set. """ try: obj.action except AttributeError: obj.add('action').value = 'AUDIO' try: obj.trigger except AttributeError: obj.add('trigger').value = datetime.timedelta(0) @classmethod def validate(cls, obj, raiseException, *args): """ # TODO if obj.contents.has_key('dtend') and obj.contents.has_key('duration'): if raiseException: m = "VEVENT components cannot contain both DTEND and DURATION\ components" raise ValidateError(m) return False else: return super(VEvent, cls).validate(obj, raiseException, *args) """ return True registerBehavior(VAlarm) class VAvailability(VCalendarComponentBehavior): """ Availability state behavior. Used to represent user's available time slots. """ name='VAVAILABILITY' description='A component used to represent a user\'s available time slots.' sortFirst = ('uid', 'dtstart', 'duration', 'dtend') knownChildren = {'UID': (1, 1, None), # min, max, behaviorRegistry id 'DTSTAMP': (1, 1, None), 'BUSYTYPE': (0, 1, None), 'CREATED': (0, 1, None), 'DTSTART': (0, 1, None), 'LAST-MODIFIED': (0, 1, None), 'ORGANIZER': (0, 1, None), 'SEQUENCE': (0, 1, None), 'SUMMARY': (0, 1, None), 'URL': (0, 1, None), 'DTEND': (0, 1, None), 'DURATION': (0, 1, None), 'CATEGORIES': (0, None, None), 'COMMENT': (0, None, None), 'CONTACT': (0, None, None), 'AVAILABLE': (0, None, None), } @classmethod def validate(cls, obj, raiseException, *args): if 'dtend' in obj.contents and 'duration' in obj.contents: if raiseException: m = "VAVAILABILITY components cannot contain both DTEND and DURATION components" raise ValidateError(m) return False else: return super(VAvailability, cls).validate(obj, raiseException, *args) registerBehavior(VAvailability) class Available(RecurringBehavior): """ Event behavior. """ name='AVAILABLE' sortFirst = ('uid', 'recurrence-id', 'dtstart', 'duration', 'dtend') description='Defines a period of time in which a user is normally available.' knownChildren = {'DTSTAMP': (1, 1, None), # min, max, behaviorRegistry id 'DTSTART': (1, 1, None), 'UID': (1, 1, None), 'DTEND': (0, 1, None), # NOTE: One of DtEnd or 'DURATION': (0, 1, None), # Duration must appear, but not both 'CREATED': (0, 1, None), 'LAST-MODIFIED':(0, 1, None), 'RECURRENCE-ID':(0, 1, None), 'RRULE': (0, 1, None), 'SUMMARY': (0, 1, None), 'CATEGORIES': (0, None, None), 'COMMENT': (0, None, None), 'CONTACT': (0, None, None), 'EXDATE': (0, None, None), 'RDATE': (0, None, None), } @classmethod def validate(cls, obj, raiseException, *args): has_dtend = 'dtend' in obj.contents has_duration = 'duration' in obj.contents if has_dtend and has_duration: if raiseException: m = "AVAILABLE components cannot contain both DTEND and DURATION\ properties" raise ValidateError(m) return False elif not (has_dtend or has_duration): if raiseException: m = "AVAILABLE components must contain one of DTEND or DURATION\ properties" raise ValidateError(m) return False else: return super(Available, cls).validate(obj, raiseException, *args) registerBehavior(Available) class Duration(behavior.Behavior): """ Behavior for Duration ContentLines. Transform to datetime.timedelta. """ name = 'DURATION' hasNative = True @staticmethod def transformToNative(obj): """ Turn obj.value into a datetime.timedelta. """ if obj.isNative: return obj obj.isNative = True obj.value=obj.value if obj.value == '': return obj else: deltalist=stringToDurations(obj.value) # When can DURATION have multiple durations? For now: if len(deltalist) == 1: obj.value = deltalist[0] return obj else: raise ParseError("DURATION must have a single duration string.") @staticmethod def transformFromNative(obj): """ Replace the datetime.timedelta in obj.value with an RFC2445 string. """ if not obj.isNative: return obj obj.isNative = False obj.value = timedeltaToString(obj.value) return obj registerBehavior(Duration) class Trigger(behavior.Behavior): """ DATE-TIME or DURATION """ name='TRIGGER' description='This property specifies when an alarm will trigger.' hasNative = True forceUTC = True @staticmethod def transformToNative(obj): """ Turn obj.value into a timedelta or datetime. """ if obj.isNative: return obj value = getattr(obj, 'value_param', 'DURATION').upper() if hasattr(obj, 'value_param'): del obj.value_param if obj.value == '': obj.isNative = True return obj elif value == 'DURATION': try: return Duration.transformToNative(obj) except ParseError: logger.warning("TRIGGER not recognized as DURATION, trying " "DATE-TIME, because iCal sometimes exports " "DATE-TIMEs without setting VALUE=DATE-TIME") try: obj.isNative = False dt = DateTimeBehavior.transformToNative(obj) return dt except: msg = "TRIGGER with no VALUE not recognized as DURATION " \ "or as DATE-TIME" raise ParseError(msg) elif value == 'DATE-TIME': # TRIGGERs with DATE-TIME values must be in UTC, we could validate # that fact, for now we take it on faith. return DateTimeBehavior.transformToNative(obj) else: raise ParseError("VALUE must be DURATION or DATE-TIME") @staticmethod def transformFromNative(obj): if type(obj.value) == datetime.datetime: obj.value_param = 'DATE-TIME' return UTCDateTimeBehavior.transformFromNative(obj) elif type(obj.value) == datetime.timedelta: return Duration.transformFromNative(obj) else: raise NativeError("Native TRIGGER values must be timedelta or " "datetime") registerBehavior(Trigger) class PeriodBehavior(behavior.Behavior): """ A list of (date-time, timedelta) tuples. """ hasNative = True @staticmethod def transformToNative(obj): """ Convert comma separated periods into tuples. """ if obj.isNative: return obj obj.isNative = True if obj.value == '': obj.value = [] return obj tzinfo = getTzid(getattr(obj, 'tzid_param', None)) obj.value = [stringToPeriod(x, tzinfo) for x in obj.value.split(",")] return obj @classmethod def transformFromNative(cls, obj): """ Convert the list of tuples in obj.value to strings. """ if obj.isNative: obj.isNative = False transformed = [] for tup in obj.value: transformed.append(periodToString(tup, cls.forceUTC)) if len(transformed) > 0: tzid = TimezoneComponent.registerTzinfo(tup[0].tzinfo) if not cls.forceUTC and tzid is not None: obj.tzid_param = tzid obj.value = ','.join(transformed) return obj class FreeBusy(PeriodBehavior): """ Free or busy period of time, must be specified in UTC. """ name = 'FREEBUSY' forceUTC = True registerBehavior(FreeBusy, 'FREEBUSY') class RRule(behavior.Behavior): """ Dummy behavior to avoid having RRULEs being treated as text lines (and thus having semi-colons inaccurately escaped). """ registerBehavior(RRule, 'RRULE') registerBehavior(RRule, 'EXRULE') # ------------------------ Registration of common classes ---------------------- utcDateTimeList = ['LAST-MODIFIED', 'CREATED', 'COMPLETED', 'DTSTAMP'] list(map(lambda x: registerBehavior(UTCDateTimeBehavior, x), utcDateTimeList)) dateTimeOrDateList = ['DTEND', 'DTSTART', 'DUE', 'RECURRENCE-ID'] list(map(lambda x: registerBehavior(DateOrDateTimeBehavior, x), dateTimeOrDateList)) registerBehavior(MultiDateBehavior, 'RDATE') registerBehavior(MultiDateBehavior, 'EXDATE') textList = ['CALSCALE', 'METHOD', 'PRODID', 'CLASS', 'COMMENT', 'DESCRIPTION', 'LOCATION', 'STATUS', 'SUMMARY', 'TRANSP', 'CONTACT', 'RELATED-TO', 'UID', 'ACTION', 'BUSYTYPE'] list(map(lambda x: registerBehavior(TextBehavior, x), textList)) list(map(lambda x: registerBehavior(MultiTextBehavior, x), ['CATEGORIES', 'RESOURCES'])) registerBehavior(SemicolonMultiTextBehavior, 'REQUEST-STATUS') # ------------------------ Serializing helper functions ------------------------ def numToDigits(num, places): """ Helper, for converting numbers to textual digits. """ s = str(num) if len(s) < places: return ("0" * (places - len(s))) + s elif len(s) > places: return s[len(s)-places: ] else: return s def timedeltaToString(delta): """ Convert timedelta to an ical DURATION. """ if delta.days == 0: sign = 1 else: sign = delta.days / abs(delta.days) delta = abs(delta) days = delta.days hours = int(delta.seconds / 3600) minutes = int((delta.seconds % 3600) / 60) seconds = int(delta.seconds % 60) output = '' if sign == -1: output += '-' output += 'P' if days: output += '{}D'.format(days) if hours or minutes or seconds: output += 'T' elif not days: # Deal with zero duration output += 'T0S' if hours: output += '{}H'.format(hours) if minutes: output += '{}M'.format(minutes) if seconds: output += '{}S'.format(seconds) return output def timeToString(dateOrDateTime): """ Wraps dateToString and dateTimeToString, returning the results of either based on the type of the argument """ if hasattr(dateOrDateTime, 'hour'): return dateTimeToString(dateOrDateTime) return dateToString(dateOrDateTime) def dateToString(date): year = numToDigits( date.year, 4 ) month = numToDigits( date.month, 2 ) day = numToDigits( date.day, 2 ) return year + month + day def dateTimeToString(dateTime, convertToUTC=False): """ Ignore tzinfo unless convertToUTC. Output string. """ if dateTime.tzinfo and convertToUTC: dateTime = dateTime.astimezone(utc) datestr = "{0}{1}{2}T{3}{4}{5}".format( numToDigits( dateTime.year, 4), numToDigits( dateTime.month, 2), numToDigits( dateTime.day, 2), numToDigits( dateTime.hour, 2), numToDigits( dateTime.minute, 2), numToDigits( dateTime.second, 2), ) if tzinfo_eq(dateTime.tzinfo, utc): datestr += "Z" return datestr def deltaToOffset(delta): absDelta = abs(delta) hours = int(absDelta.seconds / 3600) hoursString = numToDigits(hours, 2) minutesString = '00' if absDelta == delta: signString = "+" else: signString = "-" return signString + hoursString + minutesString def periodToString(period, convertToUTC=False): txtstart = dateTimeToString(period[0], convertToUTC) if isinstance(period[1], datetime.timedelta): txtend = timedeltaToString(period[1]) else: txtend = dateTimeToString(period[1], convertToUTC) return txtstart + "/" + txtend # ----------------------- Parsing functions ------------------------------------ def isDuration(s): s = s.upper() return (s.find("P") != -1) and (s.find("P") < 2) def stringToDate(s): year = int( s[0:4] ) month = int( s[4:6] ) day = int( s[6:8] ) return datetime.date(year,month,day) def stringToDateTime(s, tzinfo=None): """ Returns datetime.datetime object. """ try: year = int( s[0:4] ) month = int( s[4:6] ) day = int( s[6:8] ) hour = int( s[9:11] ) minute = int( s[11:13] ) second = int( s[13:15] ) if len(s) > 15: if s[15] == 'Z': tzinfo = utc except: raise ParseError("'{0!s}' is not a valid DATE-TIME".format(s)) year = year and year or 2000 return datetime.datetime(year, month, day, hour, minute, second, 0, tzinfo) # DQUOTE included to work around iCal's penchant for backslash escaping it, # although it isn't actually supposed to be escaped according to rfc2445 TEXT escapableCharList = '\\;,Nn"' def stringToTextValues(s, listSeparator=',', charList=None, strict=False): """ Returns list of strings. """ if charList is None: charList = escapableCharList def escapableChar (c): return c in charList def error(msg): if strict: raise ParseError(msg) else: logging.error(msg) # vars which control state machine charIterator = enumerate(s) state = "read normal" current = [] results = [] while True: try: charIndex, char = next(charIterator) except: char = "eof" if state == "read normal": if char == '\\': state = "read escaped char" elif char == listSeparator: state = "read normal" current = "".join(current) results.append(current) current = [] elif char == "eof": state = "end" else: state = "read normal" current.append(char) elif state == "read escaped char": if escapableChar(char): state = "read normal" if char in 'nN': current.append('\n') else: current.append(char) else: state = "read normal" # leave unrecognized escaped characters for later passes current.append('\\' + char) elif state == "end": # an end state if len(current) or len(results) == 0: current = "".join(current) results.append(current) return results elif state == "error": # an end state return results else: state = "error" error("unknown state: '{0!s}' reached in {1!s}".format(state, s)) def stringToDurations(s, strict=False): """ Returns list of timedelta objects. """ def makeTimedelta(sign, week, day, hour, minute, sec): if sign == "-": sign = -1 else: sign = 1 week = int(week) day = int(day) hour = int(hour) minute = int(minute) sec = int(sec) return sign * datetime.timedelta(weeks=week, days=day, hours=hour, minutes=minute, seconds=sec) def error(msg): if strict: raise ParseError(msg) else: raise ParseError(msg) # vars which control state machine charIterator = enumerate(s) state = "start" durations = [] current = "" sign = None week = 0 day = 0 hour = 0 minute = 0 sec = 0 while True: try: charIndex, char = next(charIterator) except: char = "eof" if state == "start": if char == '+': state = "start" sign = char elif char == '-': state = "start" sign = char elif char.upper() == 'P': state = "read field" elif char == "eof": state = "error" error("got end-of-line while reading in duration: " + s) elif char in string.digits: state = "read field" current = current + char # update this part when updating "read field" else: state = "error" error("got unexpected character {0} reading in duration: {1}" .format(char, s)) elif state == "read field": if (char in string.digits): state = "read field" current = current + char # update part above when updating "read field" elif char.upper() == 'T': state = "read field" elif char.upper() == 'W': state = "read field" week = current current = "" elif char.upper() == 'D': state = "read field" day = current current = "" elif char.upper() == 'H': state = "read field" hour = current current = "" elif char.upper() == 'M': state = "read field" minute = current current = "" elif char.upper() == 'S': state = "read field" sec = current current = "" elif char == ",": state = "start" durations.append(makeTimedelta(sign, week, day, hour, minute, sec)) current = "" sign = None week = None day = None hour = None minute = None sec = None elif char == "eof": state = "end" else: state = "error" error("got unexpected character reading in duration: " + s) elif state == "end": # an end state if (sign or week or day or hour or minute or sec): durations.append(makeTimedelta(sign, week, day, hour, minute, sec)) return durations elif state == "error": # an end state error("in error state") return durations else: state = "error" error("unknown state: '{0!s}' reached in {1!s}".format(state, s)) def parseDtstart(contentline, allowSignatureMismatch=False): """ Convert a contentline's value into a date or date-time. A variety of clients don't serialize dates with the appropriate VALUE parameter, so rather than failing on these (technically invalid) lines, if allowSignatureMismatch is True, try to parse both varieties. """ tzinfo = getTzid(getattr(contentline, 'tzid_param', None)) valueParam = getattr(contentline, 'value_param', 'DATE-TIME').upper() if valueParam == "DATE": return stringToDate(contentline.value) elif valueParam == "DATE-TIME": try: return stringToDateTime(contentline.value, tzinfo) except: if allowSignatureMismatch: return stringToDate(contentline.value) else: raise def stringToPeriod(s, tzinfo=None): values = s.split("/") start = stringToDateTime(values[0], tzinfo) valEnd = values[1] if isDuration(valEnd): # period-start = date-time "/" dur-value delta = stringToDurations(valEnd)[0] return (start, delta) else: return (start, stringToDateTime(valEnd, tzinfo)) def getTransition(transitionTo, year, tzinfo): """ Return the datetime of the transition to/from DST, or None. """ def firstTransition(iterDates, test): """ Return the last date not matching test, or None if all tests matched. """ success = None for dt in iterDates: if not test(dt): success = dt else: if success is not None: return success return success # may be None def generateDates(year, month=None, day=None): """ Iterate over possible dates with unspecified values. """ months = range(1, 13) days = range(1, 32) hours = range(0, 24) if month is None: for month in months: yield datetime.datetime(year, month, 1) elif day is None: for day in days: try: yield datetime.datetime(year, month, day) except ValueError: pass else: for hour in hours: yield datetime.datetime(year, month, day, hour) assert transitionTo in ('daylight', 'standard') if transitionTo == 'daylight': def test(dt): try: return tzinfo.dst(dt) != zeroDelta except pytz.NonExistentTimeError: return True # entering daylight time except pytz.AmbiguousTimeError: return False # entering standard time elif transitionTo == 'standard': def test(dt): try: return tzinfo.dst(dt) == zeroDelta except pytz.NonExistentTimeError: return False # entering daylight time except pytz.AmbiguousTimeError: return True # entering standard time newyear = datetime.datetime(year, 1, 1) monthDt = firstTransition(generateDates(year), test) if monthDt is None: return newyear elif monthDt.month == 12: return None else: # there was a good transition somewhere in a non-December month month = monthDt.month day = firstTransition(generateDates(year, month), test).day uncorrected = firstTransition(generateDates(year, month, day), test) if transitionTo == 'standard': # assuming tzinfo.dst returns a new offset for the first # possible hour, we need to add one hour for the offset change # and another hour because firstTransition returns the hour # before the transition return uncorrected + datetime.timedelta(hours=2) else: return uncorrected + datetime.timedelta(hours=1) def tzinfo_eq(tzinfo1, tzinfo2, startYear = 2000, endYear=2020): """ Compare offsets and DST transitions from startYear to endYear. """ if tzinfo1 == tzinfo2: return True elif tzinfo1 is None or tzinfo2 is None: return False def dt_test(dt): if dt is None: return True return tzinfo1.utcoffset(dt) == tzinfo2.utcoffset(dt) if not dt_test(datetime.datetime(startYear, 1, 1)): return False for year in range(startYear, endYear): for transitionTo in 'daylight', 'standard': t1=getTransition(transitionTo, year, tzinfo1) t2=getTransition(transitionTo, year, tzinfo2) if t1 != t2 or not dt_test(t1): return False return True # ------------------- Testing and running functions ---------------------------- if __name__ == '__main__': import tests tests._test()