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]