mario.Database.to_region_subset#

Keep a selected subset of regions explicit while treating the remaining regions as exogenous imports and exports. This generalizes Database.to_single_region(...) to the case where more than one region must remain endogenous.

Database.to_region_subset(regions, inplace=True, trade_mode='aggregate')#

Keep one explicit region subset and externalize the remaining regions.

Parameters:

  • regions – One region label or an iterable of region labels to keep explicit.

  • inplace – When True, mutate the current database. When False, return a transformed copy.

  • trade_mode – "aggregate" collapses the excluded regions into one aggregated imports row plus export categories. "by_region" keeps one explicit import row and one explicit export category per excluded region.

Returns:

Transformed database when inplace=False, otherwise None.

Return type:

Database | None

Notes

The selected regions keep their endogenous transactions with each other. All excluded regions are moved outside the endogenous system and are represented as exogenous imports and exports.

Use trade_mode="aggregate" to collapse the excluded regions into a single imports row plus aggregate export categories, or trade_mode="by_region" to preserve one import row and one export category per excluded region.

Examples

Keep IT and FR explicit while treating the remaining regions as exogenous trade:

subset = db.to_region_subset(["IT", "FR"], inplace=False)

Keep the same subset but preserve exogenous trade partner detail:

subset = db.to_region_subset(
    ["IT", "FR"],
    inplace=False,
    trade_mode="by_region",
)