Merge pull request #377 from badiku/graphviz_options

allow passing additional options to graphviz, fix #332

Author: martindurant

streamz/graph.py

@@ -131,7 +131,14 @@ def readable_graph(graph):
 def to_graphviz(graph, **graph_attr):
     import graphviz
 
-    gvz = graphviz.Digraph(graph_attr=graph_attr)
+    digraph_kwargs = {'name', 'comment', 'filename',
+                      'format', 'engine', 'encoding',
+                      'graph_attr', 'node_attr', 'edge_attr',
+                      'body', 'strict', 'directory'}
+    if not digraph_kwargs.intersection(graph_attr):
+        graph_attr = dict(graph_attr=graph_attr)
+
+    gvz = graphviz.Digraph(**graph_attr)
     for node, attrs in graph.nodes.items():
         gvz.node(node, **attrs)
     for edge, attrs in graph.edges().items():