Added testing for Schulze functions. (#104)

* Added pandas and pytest to requirements.txt

* updated module name in test_main.py

* Wrote tests for schulze

* Removed dead code

* Updated license

* Updated dates

Author: CheatCodeSam

.gitignore

@@ -18,4 +18,7 @@ build/
 
 **/*/node_modules
 
-/meta/
+/meta/
+
+test/*.db
+test/meta

elekto/core/__init__.py

@@ -20,9 +20,11 @@
 """
 
 from collections import defaultdict
+from typing import Dict, List, Tuple
+from .types import BallotType
 
-
-def schulze_d(candidates, ballots):
+# Higher rank numbers receive higher preference
+def schulze_d(candidates: List[str], ballots: BallotType):
     d = {(V, W): 0 for V in candidates for W in candidates if V != W}
     for voter in ballots.keys():
         for V, Vr in ballots[voter]:
@@ -33,7 +35,7 @@ def schulze_d(candidates, ballots):
     return d
 
 
-def schulze_p(candidates, d):
+def schulze_p(candidates: List[str], d: Dict[Tuple[str, str], int]):
     p = {}
     for X in candidates:
         for Y in candidates:
@@ -52,7 +54,7 @@ def schulze_p(candidates, d):
     return p
 
 
-def schulze_rank(candidates, p, no_winners=1):
+def schulze_rank(candidates: List[str], p: Dict[Tuple[str, str], int], no_winners=1):
     wins = defaultdict(list)
 
     for V in candidates:

elekto/core/election.py

@@ -14,20 +14,23 @@
 #
 # Author(s):         Manish Sahani <rec.manish.sahani@gmail.com>
 
+from typing import List
+from .types import BallotType
+from pandas import DataFrame
 from elekto.core import schulze_d, schulze_p, schulze_rank
 
-
 class Election:
-    def __init__(self, candidates, ballots):
+    def __init__(self, candidates: List[str], ballots: BallotType, no_winners=1):
         self.candidates = candidates
         self.ballots = ballots
+        self.no_winners = no_winners
         self.d = {}
         self.p = {}
 
     def schulze(self):
         self.d = schulze_d(self.candidates, self.ballots)
         self.p = schulze_p(self.candidates, self.d)
-        self.ranks = schulze_rank(self.candidates, self.p)
+        self.ranks = schulze_rank(self.candidates, self.p, self.no_winners)
 
         return self
 
@@ -46,9 +49,9 @@ def build(candidates, ballots):
         return Election(candidates, pref)
 
     @ staticmethod
-    def from_csv(df, no_winners):
+    def from_csv(df: DataFrame, no_winners: int):
         candidates = list(df.columns)
-        ballots = {}
+        ballots: BallotType = {}
 
         for v, row in df.iterrows():
             ballots[v] = []

elekto/core/types.py

@@ -0,0 +1,19 @@
+# Copyright 2024 The Elekto Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Author(s):         Carson Weeks <mail@carsonweeks.com>
+
+from typing import Dict, List, Tuple, TypeAlias
+
+BallotType: TypeAlias = Dict[int, List[Tuple[str, int]]]

requirements.txt

@@ -1,12 +1,37 @@
-Flask>=2.0.3
-python-dotenv>=0.19.2
-requests>=2.27.1
-PyYAML>=6.0
-authlib>=0.15.5
-SQLAlchemy==1.4.49
-mysqlclient>=2.1.0
-psycopg2>=2.9.3
-markdown2>=2.4.2
-uwsgi>=2.0.20
-Flask-WTF>=1.0.0
-PyNaCl>=1.5.0
+authlib==1.4.0
+blinker==1.9.0
+certifi==2024.12.14
+cffi==1.17.1
+charset-normalizer==3.4.1
+click==8.1.8
+cryptography==44.0.0
+flask==3.1.0
+flask-wtf==1.2.2
+greenlet==3.1.1
+idna==3.10
+iniconfig==2.0.0
+itsdangerous==2.2.0
+jinja2==3.1.5
+markdown2==2.5.2
+markupsafe==3.0.2
+mysqlclient==2.2.7
+numpy==2.2.2
+packaging==24.2
+pandas==2.2.3
+pluggy==1.5.0
+psycopg2==2.9.10
+pycparser==2.22
+pynacl==1.5.0
+pytest==8.3.4
+python-dateutil==2.9.0.post0
+python-dotenv==1.0.1
+pytz==2024.2
+pyyaml==6.0.2
+requests==2.32.3
+six==1.17.0
+sqlalchemy==1.4.49
+tzdata==2025.1
+urllib3==2.3.0
+uwsgi==2.0.28
+werkzeug==3.1.3
+wtforms==3.2.1

test/.gitignore

@@ -0,0 +1,15 @@
+# Copyright 2025 The Elekto Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Author(s):         Carson Weeks <mail@carsonweeks.com>

test/__init__.py

@@ -0,0 +1,103 @@
+# Copyright 2025 The Elekto Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Author(s):         Carson Weeks <mail@carsonweeks.com>
+
+import os
+import sys
+import pytest
+
+from elekto.core import schulze_d, schulze_p, schulze_rank  # noqa
+
+def test_schulze_d():
+    candidates = ["A", "B", "C"]
+    ballots = {
+        "voter1": [("A", 3), ("B", 2), ("C", 1)],
+        "voter2": [("B", 3), ("C", 2), ("A", 1)]
+    }
+
+    expected_d = {
+        ("A", "B"): 1,
+        ("A", "C"): 1,
+        ("B", "A"): 1,
+        ("B", "C"): 2,
+        ("C", "A"): 1,
+        ("C", "B"): 0,
+    }
+
+    result = schulze_d(candidates, ballots)
+    print(result)
+    assert result == expected_d
+
+def test_schulze_p():
+    candidates = ["A", "B", "C", "D"]
+    d = {
+        ("A", "B"): 12, ("B", "A"):  9,
+        ("A", "C"):  7, ("C", "A"): 14,
+        ("A", "D"): 16, ("D", "A"):  3,
+        ("B", "C"):  5, ("C", "B"): 10,
+        ("B", "D"): 18, ("D", "B"):  1,
+        ("C", "D"):  2, ("D", "C"): 20,
+    }
+
+    expected_p = {
+        ("A", "B"): 12,
+        ("B", "A"): 14,
+        ("A", "C"): 16,
+        ("C", "A"): 14,
+        ("A", "D"): 16,
+        ("D", "A"): 14,
+        ("B", "C"): 18,
+        ("C", "B"): 12,
+        ("B", "D"): 18,
+        ("D", "B"): 12,
+        ("C", "D"): 14,
+        ("D", "C"): 20,
+    }
+
+    result = schulze_p(candidates, d)
+    print(result)
+    assert result == expected_p
+
+def test_schulze_rank_simple():
+    candidates = ["A", "B", "C"]
+    p = {
+        ("A", "B"): 10,  ("B", "A"): 5,
+        ("A", "C"): 15,  ("C", "A"): 2,
+        ("B", "C"):  8,  ("C", "B"): 3,
+    }
+
+    expected = [
+        (0, ["C"]),
+        (1, ["B"]),
+        (2, ["A"])
+    ]
+
+    result = schulze_rank(candidates, p)
+    assert result == expected
+
+def test_schulze_rank_tie():
+    candidates = ["A", "B", "C"]
+    p = {
+        ("A", "B"): 10, ("B", "A"):  5,
+        ("B", "C"): 10, ("C", "B"):  5,
+        ("C", "A"): 10, ("A", "C"):  5,
+    }
+    expected = [
+        (1, ["A", "B", "C"])
+    ]
+
+    result = schulze_rank(candidates, p)
+    assert result == expected
+