bw2io.package

Module Contents

Classes

BW2Package

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

Functions

download_biosphere()
download_methods()

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
}

Warnings

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")

APPROVED

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

objobject

Object to export.

filenamestr, optional

Name of file to create. Default is obj.name.

folderstr, optional

Folder to create file in. Default is export.

backwards_compatiblebool, optional

Create package compatible with bw2data version 1.

Returns

str

Filepath of created file.

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

Export a list of objects. Can have heterogeneous types.

Parameters

objslist

List of objects to export.

filenamestr

Name of file to create.

folderstr, optional

Folder to create file in. Default is export.

backwards_compatiblebool, optional

Create package compatible with bw2data version 1.

Returns

str

Filepath of created file.

classmethod import_file(filepath, whitelist=True)

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

Parameters

filepathstr

Path of file to import

whitelistbool

Apply whitelist to allowed types. Default is True.

Returns

object or list of objects

Created object or list of created objects.

classmethod load_file(filepath, whitelist=True)

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

Parameters

filepathstr

Path of file to import

whitelistbool

Apply whitelist of approved classes to allowed types. Default is True.

Returns

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

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

bw2io.package.download_biosphere()

bw2io.package.download_methods()