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Diffstat (limited to 'creactistore/_templates/lib/isodate/isoduration.py')
| -rw-r--r-- | creactistore/_templates/lib/isodate/isoduration.py | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/creactistore/_templates/lib/isodate/isoduration.py b/creactistore/_templates/lib/isodate/isoduration.py new file mode 100644 index 0000000..3554b1f --- /dev/null +++ b/creactistore/_templates/lib/isodate/isoduration.py @@ -0,0 +1,140 @@ +############################################################################## +# Copyright 2009, Gerhard Weis +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are met: +# +# * Redistributions of source code must retain the above copyright notice, +# this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright notice, +# this list of conditions and the following disclaimer in the documentation +# and/or other materials provided with the distribution. +# * Neither the name of the authors nor the names of its contributors +# may be used to endorse or promote products derived from this software +# without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +# CONTRACT, STRICT LIABILITY, OR TORT +############################################################################## +''' +This module provides an ISO 8601:2004 duration parser. + +It also provides a wrapper to strftime. This wrapper makes it easier to +format timedelta or Duration instances as ISO conforming strings. +''' +from datetime import timedelta +import re + +from isodate.duration import Duration +from isodate.isoerror import ISO8601Error +from isodate.isodatetime import parse_datetime +from isodate.isostrf import strftime, D_DEFAULT + +ISO8601_PERIOD_REGEX = re.compile(r"^(?P<sign>[+-])?" + r"P(?P<years>[0-9]+([,.][0-9]+)?Y)?" + r"(?P<months>[0-9]+([,.][0-9]+)?M)?" + r"(?P<weeks>[0-9]+([,.][0-9]+)?W)?" + r"(?P<days>[0-9]+([,.][0-9]+)?D)?" + r"((?P<separator>T)(?P<hours>[0-9]+([,.][0-9]+)?H)?" + r"(?P<minutes>[0-9]+([,.][0-9]+)?M)?" + r"(?P<seconds>[0-9]+([,.][0-9]+)?S)?)?$") +# regular expression to parse ISO duartion strings. + + +def parse_duration(datestring): + """ + Parses an ISO 8601 durations into datetime.timedelta or Duration objects. + + If the ISO date string does not contain years or months, a timedelta + instance is returned, else a Duration instance is returned. + + The following duration formats are supported: + -PnnW duration in weeks + -PnnYnnMnnDTnnHnnMnnS complete duration specification + -PYYYYMMDDThhmmss basic alternative complete date format + -PYYYY-MM-DDThh:mm:ss extended alternative complete date format + -PYYYYDDDThhmmss basic alternative ordinal date format + -PYYYY-DDDThh:mm:ss extended alternative ordinal date format + + The '-' is optional. + + Limitations: ISO standard defines some restrictions about where to use + fractional numbers and which component and format combinations are + allowed. This parser implementation ignores all those restrictions and + returns something when it is able to find all necessary components. + In detail: + it does not check, whether only the last component has fractions. + it allows weeks specified with all other combinations + + The alternative format does not support durations with years, months or + days set to 0. + """ + if not isinstance(datestring, basestring): + raise TypeError("Expecting a string %r" % datestring) + match = ISO8601_PERIOD_REGEX.match(datestring) + if not match: + # try alternative format: + if datestring.startswith("P"): + durdt = parse_datetime(datestring[1:]) + if durdt.year != 0 or durdt.month != 0: + # create Duration + ret = Duration(days=durdt.day, seconds=durdt.second, + microseconds=durdt.microsecond, + minutes=durdt.minute, hours=durdt.hour, + months=durdt.month, years=durdt.year) + else: # FIXME: currently not possible in alternative format + # create timedelta + ret = timedelta(days=durdt.day, seconds=durdt.second, + microseconds=durdt.microsecond, + minutes=durdt.minute, hours=durdt.hour) + return ret + raise ISO8601Error("Unable to parse duration string %r" % datestring) + groups = match.groupdict() + for key, val in groups.items(): + if key not in ('separator', 'sign'): + if val is None: + groups[key] = "0n" + #print groups[key] + groups[key] = float(groups[key][:-1].replace(',', '.')) + if groups["years"] == 0 and groups["months"] == 0: + ret = timedelta(days=groups["days"], hours=groups["hours"], + minutes=groups["minutes"], seconds=groups["seconds"], + weeks=groups["weeks"]) + if groups["sign"] == '-': + ret = timedelta(0) - ret + else: + ret = Duration(years=groups["years"], months=groups["months"], + days=groups["days"], hours=groups["hours"], + minutes=groups["minutes"], seconds=groups["seconds"], + weeks=groups["weeks"]) + if groups["sign"] == '-': + ret = Duration(0) - ret + return ret + + +def duration_isoformat(tduration, format=D_DEFAULT): + ''' + Format duration strings. + + This method is just a wrapper around isodate.isostrf.strftime and uses + P%P (D_DEFAULT) as default format. + ''' + # TODO: implement better decision for negative Durations. + # should be done in Duration class in consistent way with timedelta. + if ((isinstance(tduration, Duration) and (tduration.years < 0 or + tduration.months < 0 or + tduration.tdelta < timedelta(0))) + or (isinstance(tduration, timedelta) and (tduration < timedelta(0)))): + ret = '-' + else: + ret = '' + ret += strftime(tduration, format) + return ret |