A fresh start.

.gitignore

@@ -0,0 +1 @@
+**__pycache__

Makefile

@@ -1,2 +1,5 @@
+install:
+	poetry install
+
 test:
 	poetry run pytest

pyproject.toml

@@ -1,14 +1,15 @@
 [tool.poetry]
 name = "vizing"
-version = "0.1.0"
-description = "List-colouring in Python."
+version = "0.1.0.9000"
+description = "Constraint-based list-colouring in Python."
 authors = ["Matthew Henderson <[email protected]>"]
 readme = "README.md"
 
 [tool.poetry.dependencies]
 python = "^3.10"
 python-constraint = "^1.4.0"
 networkx = "^3.2.1"
+listcolouring = "^0.2.0"
 
 
 [tool.poetry.group.test.dependencies]
@@ -19,7 +20,3 @@ networkx = "^3.2.1"
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
 
-[tool.pytest.ini_options]
-pythonpath = [
-  "."
-]

src/vizing/__init__.py

@@ -0,0 +1,17 @@
+import constraint
+
+def list_colouring_problem(G):
+  P = constraint.Problem()
+  for node in G.nodes():
+    P.addVariable(node, G.nodes[node]['permissible'])
+  for edge in G.edges():
+    P.addConstraint(constraint.AllDifferentConstraint(), edge)
+  return(P)
+
+def list_colouring_solution(G):
+  P = list_colouring_problem(G)
+  S = P.getSolution()
+  for node in S:
+    G.nodes[node]['colour'] = S[node]
+  return(G)
+