README.rst

Brightway2 input and output

This package provides tools for the import, export, and management of inventory databases and impact assessment methods. It is part of the Brightway2 LCA framework. Online documentation is available, and the source code is hosted on Github.

Compatibility with Brightway2X

Until there is a solution to using seamlessly bw2io to use any flow list (to create the biosphere) regardless of the bw2io and brightway2X package version, specific versions of bw2io must be used for compatibility with specific ecoinvent versions.

This code in this repository is used to release packages for both Brightway25 (the current default branch of this repository "master") and Brightway2 (the "legacy" branch in this repository).

• For the Brightway2 compatible version, use a 0.8.X version.

  • use version 0.8.7 to have a Brightway2 installation compatible with Ecoinvent 3.8

    If you have a working environment with brightway2

    conda install -c conda-forge -c cmutel bw2io=0.8.7
    

    If you have are starting a new environment

    conda install -c conda-forge -c cmutel brightway2 bw2io=0.8.7
    

  • use version 0.8.8 to have a Brightway2 installation compatible with Ecoinvent 3.9

    conda install -c conda-forge bw2io=0.8.8 # If you have a working environment with brightway2
    conda install -c conda-forge brightway2 bw2io=0.8.8 # If you are starting a new environment
    

• For the Brightway25 compatible version, use a 0.9.X version.

  • use version 0.9.dev11 to have a Brightway2 installation compatible with Ecoinvent 3.8.

    This version is only available through pypi.

    If you already have a brightway25 environment, do

    pip install bw2io==0.9.dev11
    

  • use version 0.9.dev10 to have a Brightway2 installation compatible with Ecoinvent 3.9

    conda install -c conda-forge -c cmutel bw2io=0.9.dev10 # If you have a working environment with brightway25
    conda install -c conda-forge -c cmutel brightway25 bw2io=0.9.dev10 # If you are starting a new environment
    

TL;DR

Summing up, you need a specific version of bw2io for specific versions of ecoinvent 3.8 and 3.9.:

+------------------|-------------------|------------------+
|Ecoinvent version | Brightway Version | bw2io Version    |
+==================|===================|==================+
|ecoinvent 3.8     | bw2               | bw2io 0.8.7      |
+------------------|-------------------|------------------+
|ecoinvent 3.9     | bw2               | bw2io 0.8.8      |
+------------------|-------------------|------------------+
|ecoinvent 3.8     | bw25              | bw2io 0.9.dev11  |
+------------------|-------------------|------------------+
|ecoinvent 3.9     | bw25              | bw2io 0.9.dev10  |
+------------------|-------------------|------------------+

Bw2io approach

In contrast with previous IO functionality in Brightway2, brightway2-io uses an iterative approach to importing and linking data. 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:

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.