gv
Section: Misc. Reference Manual Pages (3python)
Updated: 17 December 2016
Page Index
NAME
gv_python - graph manipulation in python
SYNOPSIS
#!/usr/bin/python
import sys
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 a string result
-
string gv.renderresult (graph_handle ing, string format);
gv.renderresult (graph_handle, string format, string outdata);
- Render to an open channel
-
bool gv.renderchannel (graph_handle, string format, string channelname);
- 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);
- Graph transformation tools
-
bool gv.tred (graph_handle);
KEYWORDS
graph, dot, neato, fdp, circo, twopi, python.