def parse_iso8601_interval(interval_str):
"""
Parse an iso8601 time interval string.
@type interval_str: str
@param interval_str: iso8601 time interval string to parse
@rtype: tuple of (int or None, datetime.datetime or None, datetime.timedelta)
@return: a tuple of the length of the interval, the starting time of the
interval or None if not present, and number of recurrences of the
interval or None if notpresent
"""
# iso8601 supports a number of different time interval formats, however,
# only one is really useful to pulp:
# <recurrences>/<start time>/<interval duration>
# NOTE that recurrences and start time are both optional
# XXX this algorithm will mistakenly parse the format:
# <recurrences>/<interval duration>/<end time>
interval = None
start_time = None
recurrences = None
for part in _iso8601_delimiter.split(interval_str):
if _iso8601_delimiter.match(part):
continue
match = _iso8601_recurrences.match(part)
if match is not None:
if recurrences is not None:
raise isodate.ISO8601Error('Multiple recurrences specified')
recurrences = int(match.group('num'))
elif part.startswith('P'):
if interval is not None:
raise isodate.ISO8601Error(
'Multiple interval durations specified')
interval = parse_iso8601_duration(part)
else:
if start_time is not None:
raise isodate.ISO8601Error(
'Interval with start and end times is not supported')
start_time = parse_iso8601_datetime(part)
# the interval is the only required part
if interval is None:
raise isodate.ISO8601Error('No interval specification found')
# if the interval contains months or years, isodate will use it's own
# internal Duration class instead of timedelta
# pulp cannot handle Duration instances if a start_time is not provided
if isinstance(interval, isodate.Duration) and start_time is None:
raise isodate.ISO8601Error(
'Intervals with year and month values are not valid without a start time'
)
return (interval, start_time, recurrences)
def parse_iso8601_duration(duration_str):
"""
Parse an iso8601 duration string.
@type duration_str: str
@param: duration_str: iso8601 duration string to parse
@rtype: isodate.Duration or datetime.timedelta instance
"""
try:
return isodate.parse_duration(duration_str)
except (ValueError, isodate.ISO8601Error):
msg = _('Malformed ISO8601 duration string: %(d)s') % {'d': duration_str}
raise isodate.ISO8601Error(msg), None, sys.exc_info()[2]
def parse_iso8601_datetime(datetime_str):
"""
Parse an iso8601 datetime string.
@type datetime_str: str
@param datetime_str: iso8601 datetime string to parse
@rtype: datetime.datetime instance
"""
try:
return isodate.parse_datetime(datetime_str)
except (ValueError, isodate.ISO8601Error):
msg = _('Malformed ISO8601 date-time string: %(d)s') % {'d': datetime_str}
raise isodate.ISO8601Error(msg), None, sys.exc_info()[2]
def parse_datetime(datetimestring):
'''
Parses ISO 8601 date-times into datetime.datetime objects.
This function uses parse_date and parse_time to do the job, so it allows
more combinations of date and time representations, than the actual
ISO 8601:2004 standard allows.
'''
try:
datestring, timestring = re.split('T| ', datetimestring)
except ValueError:
raise isodate.ISO8601Error(
"ISO 8601 time designator 'T' or ' ' missing. Unable to parse "
"datetime string %r" % datetimestring)
tmpdate = isodate.parse_date(datestring)
tmptime = isodate.parse_time(timestring)
return datetime.datetime.combine(tmpdate, tmptime)
