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This package provides tools for the import, export, and management of inventory databases and impact assessment methods. It is part of the Brightway LCA framework <https://brightway.dev/>. Online documentation <https://2.docs.brightway.dev/> is available, and the source code is hosted on Github <https://github.com/brightway-lca/brightway2-io>_.
brightway2-io is an ETL library. First, data is extracted into a common format. Next, a series of strategies is employed to uniquely identify each dataset and link datasets internally and to the biosphere. Following internal linking, linking to other background datasets can be performed. Finally, database data is written to disk.
This approach offers a number of benefits that help mitigate some of the serious problems in existing inventory data formats: the number of unlinked exchanges can be easily seen, linking strategies can be iteratively applied, and intermediate results can be saved.
Here is a typical usage. Note that we also have shortcuts for popular LCA databases such as ecoinvent:
.. code-block:: ipython
In [1]: import bw2io as bi
In [2]: import brightway2 as bw2
In [3]: bi.version Out[3]: (0, 8, 7)
In [4]: bw2.version Out[4]: (2, 4, 1)
In [5]: importer = bi.SingleOutputEcospold2Importer('path/to/ecoinvent/datasets/', 'ei_38_cutoff') Extracting XML data from 19565 datasets Extracted 19565 datasets in 19.21 seconds
In [6]: importer.apply_strategies() Applying strategy: normalize_units Applying strategy: update_ecoinvent_locations Applying strategy: remove_zero_amount_coproducts Applying strategy: remove_zero_amount_inputs_with_no_activity Applying strategy: remove_unnamed_parameters Applying strategy: es2_assign_only_product_with_amount_as_reference_product Applying strategy: assign_single_product_as_activity Applying strategy: create_composite_code Applying strategy: drop_unspecified_subcategories Applying strategy: fix_ecoinvent_flows_pre35 Applying strategy: drop_temporary_outdated_biosphere_flows Applying strategy: link_biosphere_by_flow_uuid Applying strategy: link_internal_technosphere_by_composite_code Applying strategy: delete_exchanges_missing_activity Applying strategy: delete_ghost_exchanges Applying strategy: remove_uncertainty_from_negative_loss_exchanges Applying strategy: fix_unreasonably_high_lognormal_uncertainties Applying strategy: set_lognormal_loc_value Applying strategy: convert_activity_parameters_to_list Applying strategy: add_cpc_classification_from_single_reference_product Applying strategy: delete_none_synonyms Applied 21 strategies in 3.62 seconds
In [7]: importer.statistics() 19565 datasets 629959 exchanges 0 unlinked exchanges
Out[7]: (19565, 629959, 0)
In [8]: if importer.statistics()[2] == 0: ...: importer.write_database() ...: else: ...: print("There are unlinked exchanges.") ...: importer.write_excel() ...: 19565 datasets 629959 exchanges 0 unlinked exchanges
Writing activities to SQLite3 database: 0% [##############################] 100% | ETA: 00:00:00 Total time elapsed: 00:02:29 Title: Writing activities to SQLite3 database: Started: 11/07/2022 11:55:57 Finished: 11/07/2022 11:58:26 Total time elapsed: 00:02:29 CPU %: 32.90 Memory %: 11.17 Created database: ei_38_cutoff
Note that brightway2-io can't magically make problems in databases go away.