Merge pull request #67 from mmarkov/master

Implement changes to AGraph.clear() to handle custom attributes

pygraphviz/agraph.py

@@ -948,8 +948,8 @@ def size(self):
 
     def clear(self):
         """Remove all nodes, edges, and attributes from the graph."""
-        self.edge_attr.clear()
-        self.node_attr.clear()
+        self.remove_edges_from(self.edges())
+        self.remove_nodes_from(self.nodes())
         self.graph_attr.clear()
         # now "close" existing graph and create a new graph
         name = gv.agnameof(self.handle)

pygraphviz/tests/test_clear.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from nose.tools import *
+import pygraphviz as pgv
+
+
+def test_del():
+    A = pgv.AGraph()
+    A.add_node(1,foo='bar')
+    # For some reasons after porting to Python 3 clear often cause infinite loop
+    A.delete_node('1')
+    assert_equal(len(A), 0)
+
+def test_clear_node_with_attributes():
+    A = pgv.AGraph()
+    A.add_node(1,foo='bar')
+    # For some reasons after porting to Python 3 clear often cause infinite loop
+    A.clear()
+    assert_equal(len(A), 0)
+    assert_equal(A.nodes(), [])
+    assert_equal(A.node_attr.keys(), [])