gv(3python)
NAME
gv_python - graph manipulation in python
SYNOPSIS
#!/usr/bin/python import gv
USAGE
INTRODUCTION
gv_python is a dynamically loaded extension for python that provides
access to the graph facilities of graphviz.
COMMANDS
New graphs
- New empty graph
- graph_handle gv.graph (name);
graph_handle gv.digraph (name);
graph_handle gv.strictgraph (name);
graph_handle gv.strictdigraph (name); - New graph from a dot-syntax string or file
- graph_handle gv.readstring (string);
graph_handle gv.read (string filename);
graph_handle gv.read (channel); - Add new subgraph to existing graph
- graph_handle gv.graph (graph_handle, name);
- New nodes
- Add new node to existing graph
- node_handle gv.node (graph_handle, name);
- New edges
- Add new edge between existing nodes
- edge_handle gv.edge (tail_node_handle, head_node_handle);
- Add a new edge between an existing tail node, and a named head node which will be induced in the graph if it doesn't already exist
- edge_handle gv.edge (tail_node_handle, head_name);
- Add a new edge between an existing head node, and a named tail node which will be induced in the graph if it doesn't already exist
- edge_handle gv.edge (tail_name, head_node_handle);
- Add a new edge between named tail and head nodes which will be induced in the graph if they don't already exist
- edge_handle gv.edge (graph_handle, tail_name, head_name);
- Setting attribute values
- Set value of named attribute of graph/node/edge - creating attribute if necessary
- string gv.setv (graph_handle, attr_name, attr_value);
string gv.setv (node_handle, attr_name, attr_value);
string gv.setv (edge_handle, attr_name, attr_value); - Set value of existing attribute of graph/node/edge (using attribute handle)
- string gv.setv (graph_handle, attr_handle, attr_value);
string gv.setv (node_handle, attr_handle, attr_value);
string gv.setv (edge_handle, attr_handle, attr_value); - Getting attribute values
- Get value of named attribute of graph/node/edge
- string gv.getv (graph_handle, attr_name);
string gv.getv (node_handle, attr_name);
string gv.getv (edge_handle, attr_name); - Get value of attribute of graph/node/edge (using attribute handle)
- string gv.getv (graph_handle, attr_handle);
string gv.getv (node_handle, attr_handle);
string gv.getv (edge_handle, attr_handle); - Obtain names from handles
- string gv.nameof (graph_handle);
string gv.nameof (node_handle);
string gv.nameof (attr_handle); - Find handles from names
- graph_handle gv.findsubg (graph_handle, name);
node_handle gv.findnode (graph_handle, name);
edge_handle gv.findedge (tail_node_handle, head_node_handle);
attribute_handle gv.findattr (graph_handle, name);
attribute_handle gv.findattr (node_handle, name);
attribute_handle gv.findattr (edge_handle, name); - Misc graph navigators returning handles
- node_handle gv.headof (edge_handle);
node_handle gv.tailof (edge_handle);
graph_handle gv.graphof (graph_handle);
graph_handle gv.graphof (edge_handle);
graph_handle gv.graphof (node_handle);
graph_handle gv.rootof (graph_handle); - Obtain handles of proto node/edge for setting default attribute values
- node_handle gv.protonode (graph_handle);
edge_handle gv.protoedge (graph_handle); - Iterators
- Iteration termination tests
- bool gv.ok (graph_handle);
bool gv.ok (node_handle);
bool gv.ok (edge_handle);
bool gv.ok (attr_handle); - Iterate over subgraphs of a graph
- graph_handle gv.firstsubg (graph_handle);
graph_handle gv.nextsubg (graph_handle, subgraph_handle); - Iterate over supergraphs of a graph (obscure and rarely useful)
- graph_handle gv.firstsupg (graph_handle);
graph_handle gv.nextsupg (graph_handle, subgraph_handle); - Iterate over edges of a graph
- edge_handle gv.firstedge (graph_handle);
edge_handle gv.nextedge (graph_handle, edge_handle); - Iterate over outedges of a graph
- edge_handle gv.firstout (graph_handle);
edge_handle gv.nextout (graph_handle, edge_handle); - Iterate over edges of a node
- edge_handle gv.firstedge (node_handle);
edge_handle gv.nextedge (node_handle, edge_handle); - Iterate over out-edges of a node
- edge_handle gv.firstout (node_handle);
edge_handle gv.nextout (node_handle, edge_handle); - Iterate over head nodes reachable from out-edges of a node
- node_handle gv.firsthead (node_handle);
node_handle gv.nexthead (node_handle, head_node_handle); - Iterate over in-edges of a graph
- edge_handle gv.firstin (graph_handle);
edge_handle gv.nextin (node_handle, edge_handle); - Iterate over in-edges of a node
- edge_handle gv.firstin (node_handle);
edge_handle gv.nextin (graph_handle, edge_handle); - Iterate over tail nodes reachable from in-edges of a node
- node_handle gv.firsttail (node_handle);
node_handle gv.nexttail (node_handle, tail_node_handle); - Iterate over nodes of a graph
- node_handle gv.firstnode (graph_handle);
node_handle gv.nextnode (graph_handle, node_handle); - Iterate over nodes of an edge
- node_handle gv.firstnode (edge_handle);
node_handle gv.nextnode (edge_handle, node_handle); - Iterate over attributes of a graph
- attribute_handle gv.firstattr (graph_handle);
attribute_handle gv.nextattr (graph_handle, attr_handle); - Iterate over attributes of an edge
- attribute_handle gv.firstattr (edge_handle);
attribute_handle gv.nextattr (edge_handle, attr_handle); - Iterate over attributes of a node
- attribute_handle gv.firstattr (node_handle);
attribute_handle gv.nextattr (node_handle, attr_handle); - Remove graph objects
- bool gv.rm (graph_handle);
bool gv.rm (node_handle);
bool gv.rm (edge_handle); - Layout
- Annotate a graph with layout attributes and values using a specific layout engine
- bool gv.layout (graph_handle, string engine);
- Render
- Render a layout into attributes of the graph
- bool gv.render (graph_handle);
- Render a layout to stdout
- bool gv.render (graph_handle, string format);
- Render to an open file
- bool gv.render (graph_handle, string format, channel fout);
- Render a layout to an unopened file by name
- bool gv.render (graph_handle, string format, string filename);
- Render to an open channel
- bool gv.renderchannel (graph_handle, string format, string channelname);
- Render to a string result
- gv.renderresult (graph_handle, string format, string outdata);
- Render a layout to a malloc'ed string, to be free'd by the caller
- (deprecated - too easy to leak memory)
- (still needed for "eval [gv::renderdata $G tk]" )
- string gv.renderdata (graph_handle, string format);
- Writing graph back to file
- bool gv.write (graph_handle, string filename);
bool gv.write (graph_handle, channel);
KEYWORDS
- graph, dot, neato, fdp, circo, twopi, python.