Source code for py2neo.ext.calendar.gregorian

#!/usr/bin/env python
# -*- encoding: utf-8 -*-

# Copyright 2011-2016, Nigel Small
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


from py2neo import Node, Path, GraphError


__all__ = ["GregorianCalendar", "GregorianDate"]


[docs]class GregorianCalendar(object): """ A Gregorian calendar stored in a graph as a tree of ``(year)->(month)->(day)``. """ #: The graph associated with this calendar. graph = None __instances = {} def __new__(cls, graph): try: inst = cls.__instances[graph] except KeyError: inst = super(GregorianCalendar, cls).__new__(cls) inst.graph = graph try: inst.graph.schema.create_uniqueness_constraint("Calendar", "name") except GraphError as error: if error.__class__.__name__ == "ConstraintViolationException": pass else: raise inst.root = Node("Calendar", name="Gregorian") inst.graph.merge(inst.root) cls.__instances[graph] = inst return inst
[docs] def date(self, year, month=1, day=1): """ Pick a date from this calendar. :rtype: :class:`.GregorianDate` """ return GregorianDate(self, year, month, day)
[docs]class GregorianDate(object): """ A date picked from a :class:`.GregorianCalendar`. """ #: The calendar from which this date was picked. calendar = None #: The graph associated with this date. graph = None #: Full :class:`Path <py2neo.Path>` representing this date. path = None def __init__(self, calendar, year, month=1, day=1): self.calendar = calendar self.graph = self.calendar.graph self.path = Path(self.calendar.root, "YEAR", Node("Year", key='%04d' % year, year=year), "MONTH", Node("Month", key='%04d-%02d' % (year, month), year=year, month=month), "DAY", Node("Day", key='%04d-%02d-%02d' % (year, month, day), year=year, month=month, day=day)) self.graph.merge(self.path) @property def year(self): """ The year node for this date. :rtype: :class:`py2neo.Node` """ return self.path.nodes()[1] @property def month(self): """ The month node for this date. :rtype: :class:`py2neo.Node` """ return self.path.nodes()[2] @property def day(self): """ The day node for this date. :rtype: :class:`py2neo.Node` """ return self.path.nodes()[3]