bw2io.package

Classes

BW2Package

This is a format for saving objects which implement the datastore API.

Functions

download_biosphere()
download_methods()

Module Contents

class bw2io.package.BW2Package

Bases: object

This is a format for saving objects which implement the datastore API.

Data is stored as a BZip2-compressed file of JSON data.

This archive format is compatible across Python versions, and is, at least in theory, programming-language agnostic.

Validation is done with bw2data.validate.bw2package_validator. The data format is:

{
    'metadata': {},                                     # Dictionary of metadata to be written to metadata-store.
    'name': basestring,                                 # Name of object
    'class': {                                          # Data on the underlying class. A new class is instantiated
                                                        # based on these strings. See _create_class.
        'module': basestring,                           # e.g. "bw2data.database"
        'name': basestring                              # e.g. "Database"
    },
    'unrolled_dict': bool,                              # Flag indicating if dictionary keys needed to
                                                        # be modified for JSON (as JSON keys can't be tuples)
    'data': object                                      # Object data, e.g. LCIA method or LCI database
}

Warning

Perfect roundtrips between machines are not guaranteed:

• All lists are converted to tuples (because JSON does not distinguish between lists and tuples).

• Absolute filepaths in metadata would be specific to a certain computer and user.

Notes

This class does not need to be instantiated, as all its methods are classmethods, i.e. do BW2Package.import_obj("foo") instead of BW2Package().import_obj("foo")

classmethod _create_class(metadata, apply_whitelist=True)

classmethod _create_obj(data)

classmethod _get_class_metadata(obj)

classmethod _is_valid_package(data)

classmethod _is_whitelisted(metadata)

classmethod _load_obj(data, whitelist=True)

classmethod _prepare_obj(obj, backwards_compatible=False)

classmethod _write_file(filepath, data)

classmethod export_obj(obj, filename=None, folder='export', backwards_compatible=False)

Export an object.

Parameters:

• obj (object) – Object to export.

• filename (str, optional) – Name of file to create. Default is obj.name.

• folder (str, optional) – Folder to create file in. Default is export.

• backwards_compatible (bool, optional) – Create package compatible with bw2data version 1.

Returns:

Filepath of created file.

Return type:

str

classmethod export_objs(objs, filename, folder='export', backwards_compatible=False)

Export a list of objects. Can have heterogeneous types.

Parameters:

• objs (list) – List of objects to export.

• filename (str) – Name of file to create.

• folder (str, optional) – Folder to create file in. Default is export.

• backwards_compatible (bool, optional) – Create package compatible with bw2data version 1.

Returns:

Filepath of created file.

Return type:

str

classmethod import_file(filepath, whitelist=True)

Import bw2package file, and create the loaded objects, including registering, writing, and processing the created objects.

Parameters:

• filepath (str) – Path of file to import

• whitelist (bool) – Apply whitelist to allowed types. Default is True.

Returns:

Created object or list of created objects.

Return type:

object or list of objects

classmethod load_file(filepath, whitelist=True)

Load a bw2package file with one or more objects. Does not create new objects.

Parameters:

• filepath (str) – Path of file to import

• whitelist (bool) – Apply whitelist of approved classes to allowed types. Default is True.

Returns:

• "class" is an actual Python class object (but not instantiated).

Return type:

The loaded data in the bw2package dict data format, with the following changes

APPROVED

bw2io.package.download_biosphere()

bw2io.package.download_methods()