Run 2to3 over Doc/tools/.
diff --git a/Doc/tools/keywords.py b/Doc/tools/keywords.py
index 3344021..f9e4b03 100644
--- a/Doc/tools/keywords.py
+++ b/Doc/tools/keywords.py
@@ -21,5 +21,5 @@
 nrows = (len(l)+ncols-1)/ncols
 for i in range(nrows):
     for j in range(i, len(l), nrows):
-        print l[j].ljust(10),
-    print
+        print(l[j].ljust(10), end=' ')
+    print()