bw2io 0.9.11

Tools for importing and export life cycle inventory databases

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. Online documentation is available, and the source code is hosted on Github.

Bw2io approach

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:

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.