Add Left-Right Planarity test.

docs/source/api.rst

@@ -182,6 +182,7 @@ Other Algorithm Functions
    rustworkx.core_number
    rustworkx.graph_greedy_color
    rustworkx.metric_closure
+   rustworkx.is_planar
 
 .. _generator_funcs:
 

releasenotes/notes/is-planar-58bb8604ae00f1a1.yaml

@@ -0,0 +1,12 @@
+---
+features:
+  - |
+    Implements a new function :func:`~rustworkx.is_planar` that
+    checks whether an undirected :class:`~rustworkx.PyGraph` is planar.
+
+    .. jupyter-execute::
+
+      import rustworkx as rx
+
+      graph = rx.generators.mesh_graph(5)
+      print('Is K_5 graph planar?', rx.is_planar(graph))

rustworkx-core/src/lib.rs

@@ -73,6 +73,7 @@ pub mod centrality;
 pub mod connectivity;
 /// Module for maximum weight matching algorithms.
 pub mod max_weight_matching;
+pub mod planar;
 pub mod shortest_path;
 pub mod traversal;
 // These modules define additional data structures