bw2io.utils
===========

.. py:module:: bw2io.utils


Attributes
----------

.. autoapisummary::

   bw2io.utils.DEFAULT_FIELDS
   bw2io.utils.activity_hash


Classes
-------

.. autoapisummary::

   bw2io.utils.ExchangeLinker


Functions
---------

.. autoapisummary::

   bw2io.utils.es2_activity_hash
   bw2io.utils.format_for_logging
   bw2io.utils.load_json_data_file
   bw2io.utils.rescale_exchange
   bw2io.utils.standardize_method_to_len_3


Module Contents
---------------

.. py:class:: ExchangeLinker

   .. py:method:: activity_hash(act, fields=DEFAULT_FIELDS, case_insensitive=True, strip=True)
      :classmethod:


      Hash an activity dataset.

      Used to import data formats like ecospold 1 (ecoinvent v1-2) and SimaPro, where no unique attributes for         datasets are given. This is clearly an imperfect and brittle solution, but there is no other obvious          approach at this time.

      The fields used can be optionally specified in ``fields``.

      No fields are required; an empty string is used if a field isn't present. All fields are cast to lower case.

      By default, uses the following, in order:
          * name
          * categories
          * unit
          * reference product
          * location

      :param \* *data*: The :ref:`activity dataset data <database-documents>`.
      :type \* *data*: dict
      :param \* *fields*: Optional list of fields to hash together. Default is             ``('name', 'categories', 'unit', 'reference product', 'location')``.
      :type \* *fields*: list
      :param \* *case_insensitive*: Cast everything to lowercase before computing hash. Default is ``True``.
      :type \* *case_insensitive*: bool

      :returns: A MD5 hash string, hex-encoded.



   .. py:method:: format_nonunique_key_error(obj, fields, others)
      :staticmethod:



   .. py:method:: link_activities_to_database(activities, other=None, fields=DEFAULT_FIELDS, relink=False)
      :classmethod:



   .. py:method:: link_iterable_by_fields(unlinked, other=None, fields=DEFAULT_FIELDS, kind=None, internal=False, relink=False)
      :classmethod:


      Generic function to link objects in ``unlinked`` to objects in ``other`` using fields ``fields``.

      The database to be linked must have uniqueness for each object for the given ``fields``.

      If ``kind``, limit objects in ``unlinked`` of type ``kind``.

      If ``relink``, link to objects which already have an ``input``. Otherwise, skip already linked objects.

      If ``internal``, linked ``unlinked`` to other objects in ``unlinked``. Each object must have the attributes         ``database`` and ``code``.



   .. py:method:: overwrite_exchange_field_values_with_linked_activity_values(activities, fields=DEFAULT_FIELDS)
      :staticmethod:


      This function goes through all exchanges and copies `fields` values from the linked activity to the exchange.
      This might be helpful after linking "soft-matched" fields, such as `categories`, where a string "('air',)"
      is treated as identical to a tuple ('air',) etc.



   .. py:method:: parse_field(field_value, case_insensitive=True, strip=True, re_sub=re_sub)
      :staticmethod:



   .. py:attribute:: field_funcs


   .. py:attribute:: re_sub


.. py:function:: es2_activity_hash(activity, flow)

   Generate unique ID for ecoinvent3 dataset.

   Despite using a million UUIDs, there is actually no unique ID in an ecospold2 dataset. Datasets are uniquely identified by the combination of activity and flow UUIDs.


.. py:function:: format_for_logging(obj)

.. py:function:: load_json_data_file(filename)

.. py:function:: rescale_exchange(exc, factor)

   Rescale exchanges, including formulas and uncertainty values, by a constant factor.

   No generally recommended, but needed for use in unit conversions. Not well tested.



.. py:function:: standardize_method_to_len_3(name, padding='--', joiner=',')

   Standardize an LCIA method name to a length 3 tuple.

   ``name`` is the current name.
   ``padding`` is the string to use for missing fields.



.. py:data:: DEFAULT_FIELDS
   :value: ('name', 'categories', 'unit', 'reference product', 'location')


.. py:data:: activity_hash