spinedb_api.scenario_recipes

This module contains functions and methods to support scenario generation.

Warning

This API is experimental.

Let’s build some scenarios! Imagine we have five alternatives: Base, high_fuel, low_fuel, high_co2 and low_co2. Each scenario should use Base as the lowest rank alternative. On top of that, we want to build useful combinations of the other alternatives. First, we combine Base with all other alternatives.

import spinedb_api as api
import spinedb_api.scenario_recipes as recipes

url = "<enter url here>"

with api.DatabaseMapping(url) as db_map:
    base_alternative = db_map.alternative(name="Base")
    for alternative_name in ("high_fuel", "low_fuel", "high_co2", "low_co2"):
        scenario_name = alternative_name
        alternative = db_map.alternative(name=alternative_name)
        recipes.create_with_alternatives([base_alternative, alternative], scenario_name)

Now, we have four scenarios, high_fuel, low_fuel, high_co2 and low_co2. Each scenario has Base alternative, and one of the other alternatives corresponding to scenario’s name.

Let’s create another set of scenarios by duplicating the existing ones and adding high_co2 and low_co2 alternatives to the scenarios that deal with fuel prices.

import spinedb_api as api
import spinedb_api.scenario_recipes as recipes

url = "<enter url here>"

with api.DatabaseMapping(url) as db_map:
    for fuel in  ("high_fuel", "low_fuel"):
        for co2 in ("high_co2", "low_co2"):
            scenario_name = f"{fuel}+{co2}"
            base_scenario = db_map.scenario(name=fuel)
            new_scenario = recipes.duplicate_scenario(base_scenario, scenario_name)
            co2_alternative = db_map.alternative(name=co2)
            recipes.with_alternative(new_scenario, co2_alternative)

After running the script above, our database contains four new scenarios: high_fuel+high_co2, high_fuel+low_co2, low_fuel+high_co2 and low_fuel+low_co2.

The combinatoric iterators of the itertools module in Python’s standard library are also useful when generating scenarios based on existing alternatives. Let’s assume we have another set of alternatives which we want to combine in as many ways as possible to generate more scenarios. Again, all scenarios should have Base alternative as lowest rank alternative. The available alternatives are: coal, coal_chp, wind and antimatter.

import itertools
import spinedb_api as api
import spinedb_api.scenario_recipes as recipes

url = "<enter url here>"

with api.DatabaseMapping(url) as db_map:
    base_alternative = db_map.alternative(name="Base")
    sector_alternatives = [db_map.alternative(name=name) for name in ("coal", "coal_chp", "wind", "anti_matter")]
    for n_sectors in range(1, len(sector_alternatives) + 1):
        for sector_set in itertools.combinations(sector_alternatives, n_sectors):
            scenario_name = "+".join(alternative["name"] for alternative in sector_set)
            full_alternatives = (base_alternative,) + sector_set
            recipes.create_with_alternatives(full_alternatives, scenario_name)

itertools.combinations() creates us all sensible combinations of alternatives which result in 15 scenarios: coal, coal_chp, wind, antimatter, coal+coal_chp, coal+wind, coal+antimatter, coal_chp+wind, coal_chp+antimatter, wind+antimatter, coal+coal_chp+wind, coal+coal_chp+antimatter, coal+wind+antimatter, coal_chp+wind+antimatter and coal+coal_chp+wind+antimatter

Functions

create_with_alternatives(...)	Creates a new scenario with given alternatives.
duplicate_scenario(...)	Duplicates a scenario and its scenario alternatives.
with_alternative(→ None)	Adds an alternative to an existing scenario.
with_alternatives(→ None)	Adds given alternatives to an existing scenario.

Module Contents

spinedb_api.scenario_recipes.create_with_alternatives(alternatives: collections.abc.Sequence[spinedb_api.db_mapping_base.PublicItem], scenario_name: str) → spinedb_api.db_mapping_base.PublicItem

Creates a new scenario with given alternatives.

spinedb_api.scenario_recipes.duplicate_scenario(scenario: spinedb_api.db_mapping_base.PublicItem, duplicate_name: str) → spinedb_api.db_mapping_base.PublicItem

Duplicates a scenario and its scenario alternatives.

spinedb_api.scenario_recipes.with_alternative(scenario: spinedb_api.db_mapping_base.PublicItem, alternative: spinedb_api.db_mapping_base.PublicItem) → None

Adds an alternative to an existing scenario.

The alternative will be added as the highest ranking alternative.

spinedb_api.scenario_recipes.with_alternatives(scenario: spinedb_api.db_mapping_base.PublicItem, alternatives: collections.abc.Iterable[spinedb_api.db_mapping_base.PublicItem]) → None

Adds given alternatives to an existing scenario.

The alternatives will be added as the highest ranking alternatives.