Source code for oemof.solph._groupings

# -*- coding: utf-8 -*-

"""Groupings needed on an energy system for it to work with solph.

If you want to use solph on an energy system, you need to create it with these
groupings specified like this:

    .. code-block:: python

        from oemof.network import EnergySystem
        import oemof.solph as solph

        energy_system = EnergySystem(groupings=solph.GROUPINGS)

SPDX-FileCopyrightText: Uwe Krien <krien@uni-bremen.de>
SPDX-FileCopyrightText: Simon Hilpert
SPDX-FileCopyrightText: Cord Kaldemeyer
SPDX-FileCopyrightText: Stephan Günther
SPDX-FileCopyrightText: Saeed Sayadi
SPDX-FileCopyrightText: Johannes Kochems

SPDX-License-Identifier: MIT
"""

from oemof.network import groupings as groupings

from oemof.solph.flows._invest_non_convex_flow_block import (
    InvestNonConvexFlowBlock,
)
from oemof.solph.flows._investment_flow_block import InvestmentFlowBlock
from oemof.solph.flows._non_convex_flow_block import NonConvexFlowBlock
from oemof.solph.flows._simple_flow_block import SimpleFlowBlock


def constraint_grouping(node, fallback=lambda *xs, **ks: None):
    """Grouping function for constraints.

    This function can be passed in a list to :attr:`groupings` of
    :class:`oemof.solph.network.EnergySystem`.

    Parameters
    ----------
    node : :class:`Node <oemof.network.Node`
        The node for which the figure out a constraint group.
    fallback : callable, optional
        A function of one argument. If `node` doesn't have a `constraint_group`
        attribute, this is used to group the node instead. Defaults to not
        group the node at all.
    """
    # TODO: Refactor this for looser coupling between modules.
    # This code causes an unwanted tight coupling between the `groupings` and
    # `network` modules, resulting in having to do an import at runtime in the
    # init method of solph's `EnergySystem`. A better way would be to add a
    # method (maybe `constraints`, `constraint_group`, `constraint_type` or
    # something like that) to solph's node hierarchy, which gets overridden in
    # each subclass to return the appropriate value. Then we can just call the
    # method here.
    # This even gives other users/us the ability to customize/extend how
    # constraints are grouped by overriding the method in future subclasses.

    cg = getattr(node, "constraint_group", fallback)
    return cg()


standard_flow_grouping = groupings.FlowsWithNodes(constant_key=SimpleFlowBlock)


def _investment_grouping(stf):
    if hasattr(stf[2], "investment"):
        if stf[2].investment is not None and stf[2].nonconvex is None:
            return True
    return False


investment_flow_grouping = groupings.FlowsWithNodes(
    constant_key=InvestmentFlowBlock,
    # stf: a tuple consisting of (source, target, flow), so stf[2] is the flow.
    filter=_investment_grouping,
)


def _nonconvex_grouping(stf):
    if hasattr(stf[2], "nonconvex"):
        if stf[2].nonconvex is not None and stf[2].investment is None:
            return True
    return False


nonconvex_flow_grouping = groupings.FlowsWithNodes(
    constant_key=NonConvexFlowBlock, filter=_nonconvex_grouping
)


def _invest_non_convex_grouping(stf):
    if hasattr(stf[2], "nonconvex"):
        if stf[2].investment is not None and stf[2].nonconvex is not None:
            return True
    return False


invest_non_convex_flow_grouping = groupings.FlowsWithNodes(
    constant_key=InvestNonConvexFlowBlock, filter=_invest_non_convex_grouping
)

GROUPINGS = [
    constraint_grouping,
    investment_flow_grouping,
    standard_flow_grouping,
    nonconvex_flow_grouping,
    invest_non_convex_flow_grouping,
]