Fix problem with empty ballots when reading pb files

pabutools/__init__.py

@@ -1,3 +1,3 @@
 __author__ = "Simon Rey, Grzegorz Pierczyński, Markus Utke and Piotr Skowron"
 __email__ = "[email protected]"
-__version__ = "1.1.7"
+__version__ = "1.1.8"

pabutools/analysis/priceability.py

@@ -390,10 +390,11 @@ def priceable(
     else:
         status = mip_model.optimize(max_seconds=max_seconds)
 
-    if status == OptimizationStatus.INF_OR_UNBD:
+    if hasattr(OptimizationStatus, "INF_OR_UNBD") and status == OptimizationStatus.INF_OR_UNBD:
         # https://support.gurobi.com/hc/en-us/articles/4402704428177-How-do-I-resolve-the-error-Model-is-infeasible-or-unbounded
         # https://github.com/coin-or/python-mip/blob/1.15.0/mip/gurobi.py#L777
         # https://github.com/coin-or/python-mip/blob/1.16-pre/mip/gurobi.py#L778
+        # This is not part of old python-mip version, hence the first test
         #
         mip_model.solver.set_int_param("DualReductions", 0)
         mip_model.reset()

pabutools/election/pabulib.py

@@ -96,24 +96,27 @@ def parse_pabulib_from_string(file_content: str) -> tuple[Instance, Profile]:
             if vote_type == "approval":
                 ballot = ApprovalBallot()
                 for project_name in ballot_meta["vote"].split(","):
-                    ballot.add(instance.get_project(project_name))
+                    if project_name:
+                        ballot.add(instance.get_project(project_name))
                 ballot_meta.pop("vote")
             elif vote_type in ["scoring", "cumulative"]:
                 if vote_type == "scoring":
                     ballot = CardinalBallot()
                 else:
                     ballot = CumulativeBallot()
-                points = ballot_meta["points"].split(",")
-                for index, project_name in enumerate(ballot_meta["vote"].split(",")):
-                    ballot[instance.get_project(project_name)] = str_as_frac(
-                        points[index].strip()
-                    )
-                ballot_meta.pop("vote")
-                ballot_meta.pop("points")
+                if "points" in ballot_meta:  # if not, the ballot should be empty
+                    points = ballot_meta["points"].split(",")
+                    for index, project_name in enumerate(ballot_meta["vote"].split(",")):
+                        ballot[instance.get_project(project_name)] = str_as_frac(
+                            points[index].strip()
+                        )
+                    ballot_meta.pop("vote")
+                    ballot_meta.pop("points")
             elif vote_type == "ordinal":
                 ballot = OrdinalBallot()
                 for project_name in ballot_meta["vote"].split(","):
-                    ballot.append(instance.get_project(project_name))
+                    if project_name:
+                        ballot.append(instance.get_project(project_name))
                 ballot_meta.pop("vote")
             else:
                 raise NotImplementedError(

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "flit_core.buildapi"
 
 [project]
 name = "pabutools"
-version = "1.1.7"
+version = "1.1.8"
 description = "Implementation of all the tools necessary to explore and analyse participatory budgeting elections"
 authors = [
   { name = "Simon Rey", email = "[email protected]" },

tests/test_pabulib.py

@@ -1,6 +1,6 @@
 from unittest import TestCase
 
-from pabutools.election import OrdinalBallot
+from pabutools.election import OrdinalBallot, ApprovalBallot
 from pabutools.election.pabulib import (
     parse_pabulib,
     parse_pabulib_from_string,
@@ -93,6 +93,71 @@ def test_approval(self):
 
         os.remove("test.pb")
 
+    def test_empty_voters(self):
+        contents = """META
+key;value
+description;Auto-filled description
+country;Auto-filled country
+unit;Auto-filled unit
+instance;Auto-filled instance
+num_projects;20
+num_votes;1000
+budget;600000
+vote_type;approval
+rule;Auto-filled rule
+PROJECTS
+project_id;cost
+p0;124200
+p1;128400
+p2;135600
+p3;128400
+p4;316929
+p5;51599
+p6;66000
+p7;55200
+p8;55800
+p9;54000
+p10;66600
+p11;61199
+p12;51000
+p13;59400
+p14;59400
+p15;58800
+p16;63000
+p17;64800
+p18;66000
+p19;57600
+VOTES
+voter_id;vote
+0;p12,p19,p1,p14
+1;p11,p1,p13
+2;p16
+3;p12,p4,p9
+4;p0
+5;p12,p18,p16,p2
+6;
+7;p6,p3,p13,p17,p19
+8;p5,p10
+9;
+10;p0,p2
+11;p11,p6,p2
+12;p16,p19
+13;
+14;p10,p2"""
+
+        with open("test.pb", "w", encoding="utf-8") as f:
+            f.write(contents)
+
+        for instance, profile in [
+            parse_pabulib("test.pb"),
+            parse_pabulib_from_string(contents),
+        ]:
+            assert len(instance) == 20
+            assert len(profile) == 15
+            assert profile[6] == ApprovalBallot()
+
+        os.remove("test.pb")
+
     def test_cumulative(self):
         contents = """META
 key;value
@@ -156,7 +221,9 @@ def test_cumulative(self):
 8;14,8,2,4;3,2,1,1
 9;1,6,7,9,10,20,30;1,1,1,1,1,1,1
 10;6,7;3,3
-11;2,14,8;3,3,1"""
+11;2,14,8;3,3,1
+12;
+13;6,7;3,3"""
 
         with open("test.pb", "w", encoding="utf-8") as f:
             f.write(contents)
@@ -167,7 +234,7 @@ def test_cumulative(self):
         ]:
             assert len(instance) == 30
             assert instance.budget_limit == 1000000
-            assert len(profile) == 12
+            assert len(profile) == 14
             assert len(profile[0]) == 4
             assert len(profile[4]) == 5
 
@@ -247,7 +314,8 @@ def test_scoring(self):
 8;14,8,2,4;3,2,1,1
 9;1,6,7,9,10,20,30;1,1,1,1,1,1,1
 10;6,7;3,3
-11;2,14,8;3,3,1"""
+11;2,14,8;3,3,1
+12;"""
 
         with open("test.pb", "w", encoding="utf-8") as f:
             f.write(contents)
@@ -452,6 +520,7 @@ def test_ordinal(self):
 42;95,75,111;paper;PODGÓRZE DUCHACKIE
 43;84,101,83;internet;PODGÓRZE
 44;4,36,41;internet;KROWODRZA
+45;;internet;KROWODRZA
 """
 
         with open("test.pb", "w", encoding="utf-8") as f:
@@ -463,7 +532,7 @@ def test_ordinal(self):
         ]:
             assert len(instance) == 123
             assert instance.budget_limit == 8000100
-            assert len(profile) == 45
+            assert len(profile) == 46
             assert len(profile[44]) == 3
             assert len(profile[4]) == 3