Fix #4

Author: cmutel

README.md

@@ -88,6 +88,7 @@ To create custom allocation functions which apply a single allocation factor to
 
 * edge_data (dict): Data on functional edge
 * node: An instance of `multifunctional.MaybeMultifunctionalProcess`
+* strategy_label: An optional string to label the allocation strategy used
 
 The custom function should return a number.
 
@@ -106,7 +107,11 @@ def allocation_factor(edge_data: dict, node: mf.MaybeMultifunctionalProcess) ->
    else:
       return 7
 
-mf.allocation_strategies['silly'] = partial(mf.generic_allocation, func=allocation_factor)
+mf.allocation_strategies['silly'] = partial(
+   mf.generic_allocation,
+   func=allocation_factor,
+   strategy_label="something silly"
+)
 ```
 
 ### Other custom allocation functions

multifunctional/allocation.py

@@ -1,20 +1,24 @@
 from copy import deepcopy
 from functools import partial
-from typing import Callable, List
+from typing import Callable, List, Optional
 from uuid import uuid4
 
+from bw2data import get_node
+from bw2data.errors import UnknownObject
 from bw2io.utils import rescale_exchange
 from loguru import logger
-from bw2data.errors import UnknownObject
-from bw2data import get_node
 
 from .node_classes import (
     MaybeMultifunctionalProcess,
     ReadOnlyProcessWithReferenceProduct,
 )
 
 
-def generic_allocation(act: MaybeMultifunctionalProcess, func: Callable) -> List[dict]:
+def generic_allocation(
+    act: MaybeMultifunctionalProcess,
+    func: Callable,
+    strategy_label: Optional[str] = None,
+) -> List[dict]:
     """Allocation by single allocation factor generated by `func`.
 
     Allocation amount is edge amount times function(edge_data, act) divided by sum of all edge
@@ -74,22 +78,26 @@ def generic_allocation(act: MaybeMultifunctionalProcess, func: Callable) -> List
             )
 
         try:
-            assert not exc.get('mf_artificial_code')
+            assert not exc.get("mf_artificial_code")
             product = get_node(database=exc["input"][0], code=exc["input"][1])
         except (KeyError, UnknownObject, AssertionError):
             product = None
 
         allocated_process = deepcopy(act._data)
         if "id" in allocated_process:
             del allocated_process["id"]
+        if strategy_label:
+            allocated_process["mf_strategy_label"] = strategy_label
         allocated_process["code"] = process_code
         allocated_process["multifunctional_parent_id"] = act.id
         allocated_process["type"] = "readonly_process"
 
         if "name" in exc:
             allocated_process["reference product"] = exc["name"]
         elif product:
-            allocated_process["reference product"] = product.get("name", "(unnamed product)")
+            allocated_process["reference product"] = product.get(
+                "name", "(unnamed product)"
+            )
         else:
             allocated_process["reference product"] = "(unnamed)"
 
@@ -141,6 +149,7 @@ def property_allocation(property_label: str) -> Callable:
         func=partial(
             get_allocation_factor_from_property, property_label=property_label
         ),
+        strategy_label=f"property allocation by '{property_label}'"
     )
 
 

tests/test_allocation.py

@@ -118,6 +118,17 @@ def test_without_allocation(basic):
         assert nodes[1][key] == value
 
 
+def test_price_allocation_strategy_label(basic):
+    basic.metadata["default_allocation"] = "price"
+    bd.get_node(code="1").allocate()
+    nodes = sorted(basic, key=lambda x: (x["name"], x.get("reference product", "")))
+
+    assert not nodes[0].get("mf_strategy_label")
+    assert not nodes[1].get("mf_strategy_label")
+    assert nodes[2].get("mf_strategy_label") == "property allocation by 'price'"
+    assert nodes[3].get("mf_strategy_label") == "property allocation by 'price'"
+
+
 def test_price_allocation(basic):
     basic.metadata["default_allocation"] = "price"
     bd.get_node(code="1").allocate()

tests/test_allocation_with_products.py

@@ -9,7 +9,9 @@
 
 
 def check_products_allocation_results(factor_1, factor_2, database):
-    nodes = sorted(database, key=lambda x: (x["name"], x.get("reference product", ""), x["type"]))
+    nodes = sorted(
+        database, key=lambda x: (x["name"], x.get("reference product", ""), x["type"])
+    )
 
     assert isinstance(nodes[0], MaybeMultifunctionalProcess)
     assert nodes[0]["name"] == "first product"
@@ -105,7 +107,9 @@ def check_products_allocation_results(factor_1, factor_2, database):
 
 
 def test_without_allocation(products):
-    nodes = sorted(products, key=lambda x: (x["name"], x.get("reference product", ""), x["type"]))
+    nodes = sorted(
+        products, key=lambda x: (x["name"], x.get("reference product", ""), x["type"])
+    )
 
     assert len(nodes) == 3
 
@@ -162,7 +166,9 @@ def test_allocation_uses_existing(products):
 def test_allocation_already_allocated(products):
     products.metadata["default_allocation"] = "price"
     bd.get_node(code="1").allocate()
-    node = sorted(products, key=lambda x: (x["name"], x.get("reference product", "")))[3]
+    node = sorted(products, key=lambda x: (x["name"], x.get("reference product", "")))[
+        3
+    ]
 
     assert generic_allocation(node, None) == []