specified Python version

heineman · heineman · commit 1de93ca99ba5 · 2015-07-31T14:10:17.000-04:00
diff --git a/README.md b/README.md
@@ -22,3 +22,7 @@ Search Tree, Heaps, Binary Heaps, KD-Trees, and Quad Trees.
 Each module presents fundamental data structures and provides code examples
 demonstrating their applciation and performance. All data types are
 provided with sample code and unit tests.
+
+All code examples assumes a standard installation of Python 3.  Module 6,
+"Graph Representation", includes an example of a 3rd party library,
+pygraph, that you can install separately.
