Plot graph to graph.png in canonize_and_save_graph after setting planar positions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/colored_graphs.py

@@ -1,4 +1,4 @@
-"""Utilities for canonizing and saving colored graphs."""
+"""Utilities for canonizing and saving graphs."""
 import base64
 import tempfile
 from collections import defaultdict
@@ -53,6 +53,19 @@ def plot_colored_graph_to_data_uri(g: Graph, coloring: VertexColoring) -> str:
     return f"data:image/png;base64,{base64.b64encode(png_bytes).decode()}"
 
 
+def canonize_and_save_graph(g: Graph) -> Graph:
+    """Canonize g, save to data/graphs/<graph_id>/graph.sobj, and return the canonical graph."""
+    canonical = cast(Graph, g.canonical_label())
+    graph_id = base64.urlsafe_b64encode(canonical.graph6_string().encode()).decode()
+    out_dir = DIR / "data" / "graphs" / graph_id
+    out_dir.mkdir(parents=True, exist_ok=True)
+    print(graph_id)
+    canonical.is_planar(set_embedding=True, set_pos=True)
+    canonical.plot().save(out_dir / 'graph.png')
+    save(canonical, str(out_dir / 'graph'))
+    return canonical
+
+
 def save_colored_graph(g: Graph, coloring: VertexColoring) -> tuple[Graph, VertexColoring, ColoredGraphId]:
     """
     Canonize g and coloring, save to disk, and return the canonical forms with id.