Add single_output decorator

ocelot/model.py

@@ -17,11 +17,13 @@
 import os
 import shutil
 import sys
+import wrapt
 
 
 def apply_transformation(function, counter, data, output_dir, save_strategy):
     # A `function` can be a list of functions
-    if isinstance(function, Iterable):
+    if (isinstance(function, Iterable)
+        and not isinstance(function, wrapt.FunctionWrapper)):
         for obj in function:
             data = apply_transformation(obj, counter, data,
                                         output_dir, save_strategy)

ocelot/transformations/__init__.py

@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 from ..collection import Collection
-from ..wrapper import TransformationWrapper
 from .activity_links import (
     check_activity_link_validity,
     add_hard_linked_production_volumes,
@@ -23,5 +22,5 @@
 pv_cleanup = Collection(
     ensure_production_exchanges_have_production_volume,
     add_pv_to_allocatable_byproducts,
-    TransformationWrapper(create_pv_parameters),
+    create_pv_parameters,
 )

ocelot/transformations/cutoff/allocation.py

@@ -162,5 +162,5 @@ def allocation_method_filter(ds):
     *[TransformationWrapper(func,
                             create_allocation_filter(label))
       for label, func in ALLOCATION_METHODS[1:]],
-    TransformationWrapper(delete_allocation_method),
+    delete_allocation_method,
 )

ocelot/transformations/cutoff/utils.py

@@ -2,6 +2,7 @@
 from ..utils import (
     choose_reference_product_exchange,
     get_single_reference_product,
+    single_input,
 )
 
 
@@ -36,6 +37,7 @@ def flip_non_allocatable_byproducts(dataset):
     return dataset
 
 
+@single_input
 def delete_allocation_method(dataset):
     """Delete key ``allocation method`` if present"""
     if "allocation method" in dataset:

ocelot/transformations/cutoff/wastes.py

@@ -1,10 +1,10 @@
 # -*- coding: utf-8 -*-
 from ...collection import Collection
-from ...wrapper import TransformationWrapper
 from ..utils import (
     allocatable_production,
     choose_reference_product_exchange,
     get_single_reference_product,
+    single_input,
 )
 from ..uncertainty import scale_exchange
 from .economic import economic_allocation
@@ -142,6 +142,7 @@ def create_recycled_content_datasets(data):
 }
 
 
+@single_input
 def flip_non_allocatable_byproducts(dataset):
     """Change non-allocatable byproducts (i.e. classification ``recyclable`` or ``waste``) from outputs to technosphere to inputs from technosphere.
 
@@ -176,5 +177,5 @@ def flip_non_allocatable_byproducts(dataset):
 handle_waste_outputs = Collection(
     rename_recyclable_content_exchanges,
     create_recycled_content_datasets,
-    TransformationWrapper(flip_non_allocatable_byproducts),
+    flip_non_allocatable_byproducts,
 )

ocelot/transformations/parameterization/production_volumes.py

@@ -1,8 +1,10 @@
 # -*- coding: utf-8 -*-
+from ..utils import single_input
 import logging
 import uuid
 
 
+@single_input
 def create_pv_parameters(dataset):
     """Remove all production volume parameterization.
 

ocelot/transformations/utils.py

@@ -5,6 +5,7 @@
 from pprint import pformat
 import hashlib
 import pandas as pd
+import wrapt
 
 
 ### Activity identifiers
@@ -259,7 +260,6 @@ def choose_reference_product_exchange(dataset, exchange, allocation_factor=1):
     * ``production volume`` is deleted if present.
 
     """
-    # TODO: Make sure exchange in allocatable_production(dataset)?
     obj = deepcopy(dataset)
     if not exchange['amount']:
         message = "Zero production amount for new reference product exchange:\n{}\nIn dataset:\n{}"
@@ -277,3 +277,12 @@ def choose_reference_product_exchange(dataset, exchange, allocation_factor=1):
         for exc in nonproduction_exchanges(dataset)
     ]
     return normalize_reference_production_amount(obj)
+
+
+### Function helpers
+
+@wrapt.decorator
+def single_input(wrapped, instance, args, kwargs):
+    """Decorator to allow a transformation to transformation function to take a single dataset input."""
+    data = kwargs.get('data') or args[0]
+    return [ds for elem in data for ds in wrapped(elem)]