# -*- coding: utf-8 -*-
"""Basic EnergySystem class
This file is part of project oemof (github.com/oemof/oemof). It's copyrighted
by the contributors recorded in the version control history of the file,
available from its original location oemof/oemof/energy_system.py
SPDX-License-Identifier: MIT
"""
from collections import deque
from pickle import UnpicklingError
import logging
import os
import blinker
import dill as pickle
from oemof.groupings import DEFAULT as BY_UID, Grouping, Nodes
from oemof.network import Bus
[docs]class EnergySystem:
r"""Defining an energy supply system to use oemof's solver libraries.
Note
----
The list of regions is not necessary to use the energy system with solph.
Parameters
----------
entities : list of :class:`Entity <oemof.core.network.Entity>`, optional
A list containing the already existing :class:`Entities
<oemof.core.network.Entity>` that should be part of the energy system.
Stored in the :attr:`entities` attribute.
Defaults to `[]` if not supplied.
timeindex : pandas.datetimeindex
Define the time range and increment for the energy system.
groupings : list
The elements of this list are used to construct :class:`Groupings
<oemof.core.energy_system.Grouping>` or they are used directly if they
are instances of :class:`Grouping <oemof.core.energy_system.Grouping>`.
These groupings are then used to aggregate the entities added to this
energy system into :attr:`groups`.
By default, there'll always be one group for each :attr:`uid
<oemof.core.network.Entity.uid>` containing exactly the entity with the
given :attr:`uid <oemof.core.network.Entity.uid>`.
See the :ref:`examples <energy-system-examples>` for more information.
Attributes
----------
entities : list of :class:`Entity <oemof.core.network.Entity>`
A list containing the :class:`Entities <oemof.core.network.Entity>`
that comprise the energy system. If this :class:`EnergySystem` is
set as the :attr:`registry <oemof.core.network.Entity.registry>`
attribute, which is done automatically on :class:`EnergySystem`
construction, newly created :class:`Entities
<oemof.core.network.Entity>` are automatically added to this list on
construction.
groups : dict
results : dictionary
A dictionary holding the results produced by the energy system.
Is `None` while no results are produced.
Currently only set after a call to :meth:`optimize` after which it
holds the return value of :meth:`om.results()
<oemof.solph.optimization_model.OptimizationModel.results>`.
See the documentation of that method for a detailed description of the
structure of the results dictionary.
timeindex : pandas.index, optional
Define the time range and increment for the energy system. This is an
optional attribute but might be import for other functions/methods that
use the EnergySystem class as an input parameter.
.. _energy-system-examples:
Examples
--------
Regardles of additional groupings, :class:`entities
<oemof.core.network.Entity>` will always be grouped by their :attr:`uid
<oemof.core.network.Entity.uid>`:
>>> from oemof.network import Entity
>>> from oemof.network import Bus, Sink
>>> es = EnergySystem()
>>> bus = Bus(label='electricity')
>>> es.add(bus)
>>> bus is es.groups['electricity']
True
For simple user defined groupings, you can just supply a function that
computes a key from an :class:`entity <oemof.core.network.Entity>` and the
resulting groups will be sets of :class:`entities
<oemof.core.network.Entity>` stored under the returned keys, like in this
example, where :class:`entities <oemof.core.network.Entity>` are grouped by
their `type`:
>>> es = EnergySystem(groupings=[type])
>>> buses = set(Bus(label="Bus {}".format(i)) for i in range(9))
>>> es.add(*buses)
>>> components = set(Sink(label="Component {}".format(i))
... for i in range(9))
>>> es.add(*components)
>>> buses == es.groups[Bus]
True
>>> components == es.groups[Sink]
True
"""
signals = {}
"""A dictionary of blinker_ signals emitted by energy systems.
Currently only one signal is supported. This signal is emitted whenever a
`Node <oemof.network.Node>` is `add`ed to an energy system. The signal's
`sender` is set to the `node <oemof.network.Node>` that got added to the
energy system so that `nodes <oemof.network.Node>` have an easy way to only
receive signals for when they themselves get added to an energy system.
.. _blinker: https://pythonhosted.org/blinker/
"""
def __init__(self, **kwargs):
self._first_ungrouped_node_index_ = 0
self._groups = {}
self._groupings = ([BY_UID] +
[g if isinstance(g, Grouping) else Nodes(g)
for g in kwargs.get('groupings', [])])
self.entities = []
self.results = kwargs.get('results')
self.timeindex = kwargs.get('timeindex')
self.temporal = kwargs.get('temporal')
self.add(*kwargs.get('entities', ()))
[docs] def add(self, *nodes):
"""Add :class:`nodes <oemof.network.Node>` to this energy system."""
self.nodes.extend(nodes)
for n in nodes:
self.signals[type(self).add].send(n, EnergySystem=self)
signals[add] = blinker.signal(add)
@property
def groups(self):
gs = self._groups
deque(
(
g(n, gs)
for g in self._groupings
for n in self.nodes[self._first_ungrouped_node_index_ :]
),
maxlen=0,
)
self._first_ungrouped_node_index_ = len(self.nodes)
return self._groups
@property
def nodes(self):
return self.entities
@nodes.setter
def nodes(self, value):
self.entities = value
[docs] def flows(self):
return {(source, target): source.outputs[target]
for source in self.nodes
for target in source.outputs}
[docs] def dump(self, dpath=None, filename=None):
r""" Dump an EnergySystem instance.
"""
if dpath is None:
bpath = os.path.join(os.path.expanduser("~"), '.oemof')
if not os.path.isdir(bpath):
os.mkdir(bpath)
dpath = os.path.join(bpath, 'dumps')
if not os.path.isdir(dpath):
os.mkdir(dpath)
if filename is None:
filename = 'es_dump.oemof'
pickle.dump(self.__dict__, open(os.path.join(dpath, filename), 'wb'))
msg = ('Attributes dumped to: {0}'.format(os.path.join(
dpath, filename)))
logging.debug(msg)
return msg
[docs] def restore(self, dpath=None, filename=None):
r""" Restore an EnergySystem instance.
"""
logging.info(
"Restoring attributes will overwrite existing attributes.")
if dpath is None:
dpath = os.path.join(os.path.expanduser("~"), '.oemof', 'dumps')
if filename is None:
filename = 'es_dump.oemof'
try:
self.__dict__ = pickle.load(
open(os.path.join(dpath, filename), "rb"))
except UnpicklingError as e:
if str(e) == "state is not a dictionary":
raise UnpicklingError(
"\n "
"Seems like you're trying to load an energy system "
"dumped with an older\n "
"oemof version. Unfortunetaly we made changes which "
"broke this from\n "
"v0.2.2 (more specifically commit `bec669b`) to its "
"successor.\n "
"If you really need this functionality, please file "
"a bug entitled\n\n "
'"Pickle customization removal breaks '
'`EnergySystem.restore`"\n\n '
"at\n\n "
"https://github.com/oemof/oemof/issues\n\n "
"or comment on it if it already exists.")
raise e
msg = ('Attributes restored from: {0}'.format(os.path.join(
dpath, filename)))
logging.debug(msg)
return msg