Exchange Interface

exception antelope.interfaces.iexchange.ExchangeRequired

Bases: Exception

class antelope.interfaces.iexchange.ExchangeInterface

Bases: AbstractQuery

The Exchange Interface implements the Exchange Relation:

  • given a process, a reference flow, and a query flow, report the quantity of the query flow that is exchanged with respect to a unit of the reference flow.

exchanges(process, **kwargs)

Retrieve process’s full exchange list, without values :param process: :return: list of exchanges without values

ev(process, flow, direction=None, termination=None, ref_flow=None, **kwargs)

Return a float. Symmetric to quantity.cf

Parameters:

  • process

  • flow

  • direction – [None] if none, if flows exist with both directions, raise an error

  • termination – [None] if none, return sum of flows across all terminations

  • ref_flow – [None] if none, return unallocated value. Otherwise, return value allocated to a unit of the specified reference

Returns:

a float

exchange_values(process, flow, direction=None, termination=None, reference=None, **kwargs)

Leftover from earlier implementation; deprecated. 2022-12-27: is this really deprecated? it’s used in computing reference_value and I don’t see any other way… perhaps we should add reference_value() to the API but for now let’s keep this around

Return a list of exchanges with values matching the specification.

Parameters:

  • process

  • flow

  • direction – [None] if none,

  • termination – [None] if none, return all terminations

  • reference – [None] if True, only find reference exchanges. If false- maybe omit reference exchanges?

Returns:

list of exchanges with values matching the specification

inventory(process, ref_flow=None, scenario=None, **kwargs)

Return a list of exchanges with values. If no reference is supplied, return all unallocated exchanges, including reference exchanges.

If a reference flow is supplied, expected behavior depends on a number of factors.

  • If the supplied reference flow is part of the process’s reference entity, the inventory should return all non-reference exchanges, appropriately allocated to the specified flow, and normalized to a unit of the specified flow.

  • If the supplied reference flow is not part of the reference entity, NO allocation should be performed. Instead, the inventory should return ALL exchanges except for the specified flow, un-allocated, normalized to a unit of the specified flow. This query is only valid if the specified flow is a cut-off (i.e. un-terminated) exchange (i.e. it could be treated as a “silent reference” or effective co-product)

  • If the supplied reference flow is a non-reference, non-cutoff flow (i.e. it is a terminated exchange), then the appropriate behavior is undefined. The default implementation raises an ExchangeError.

Note: if this is called on a fragment, the signature is the same but the ‘ref_flow’ argument is ignored and the alternative ‘scenario’ kwarg is accepted

Parameters:

  • process

  • ref_flow – used only for processes

  • scenario – used only for fragments (antelope_foreground)

Returns:

a list of unallocated or allocated exchange refs

exchange_relation(process, ref_flow, exch_flow, direction, termination=None, **kwargs)

should return some sort of exchange relation result, analogous to quantity.quantity_relation

Parameters:

  • process

  • ref_flow

  • exch_flow

  • direction

  • termination

Returns:

contrib_lcia(process, quantity=None, ref_flow=None, **kwargs)

exchange interface provides the ability to perform a contribution analysis of a process’s LCIA scores. In core, this is accomplished with ephemeral fragments.

Parameters:

  • process

  • quantity – if omitted, a catalog may select a default LCIA method

  • ref_flow

  • kwargs

Returns: