"""
altgraph.Dot - Interface to the dot language
============================================
The :py:mod:`~altgraph.Dot` module provides a simple interface to the
file format used in the
`graphviz `_
program. The module is intended to offload the most tedious part of the process
(the **dot** file generation) while transparently exposing most of its
features.
To display the graphs or to generate image files the
`graphviz `_
package needs to be installed on the system, moreover the :command:`dot` and
:command:`dotty` programs must be accesible in the program path so that they
can be ran from processes spawned within the module.
Example usage
-------------
Here is a typical usage::
from altgraph import Graph, Dot
# create a graph
edges = [ (1,2), (1,3), (3,4), (3,5), (4,5), (5,4) ]
graph = Graph.Graph(edges)
# create a dot representation of the graph
dot = Dot.Dot(graph)
# display the graph
dot.display()
# save the dot representation into the mydot.dot file
dot.save_dot(file_name='mydot.dot')
# save dot file as gif image into the graph.gif file
dot.save_img(file_name='graph', file_type='gif')
Directed graph and non-directed graph
-------------------------------------
Dot class can use for both directed graph and non-directed graph
by passing ``graphtype`` parameter.
Example::
# create directed graph(default)
dot = Dot.Dot(graph, graphtype="digraph")
# create non-directed graph
dot = Dot.Dot(graph, graphtype="graph")
Customizing the output
----------------------
The graph drawing process may be customized by passing
valid :command:`dot` parameters for the nodes and edges. For a list of all
parameters see the `graphviz `_
documentation.
Example::
# customizing the way the overall graph is drawn
dot.style(size='10,10', rankdir='RL', page='5, 5' , ranksep=0.75)
# customizing node drawing
dot.node_style(1, label='BASE_NODE',shape='box', color='blue' )
dot.node_style(2, style='filled', fillcolor='red')
# customizing edge drawing
dot.edge_style(1, 2, style='dotted')
dot.edge_style(3, 5, arrowhead='dot', label='binds', labelangle='90')
dot.edge_style(4, 5, arrowsize=2, style='bold')
.. note::
dotty (invoked via :py:func:`~altgraph.Dot.display`) may not be able to
display all graphics styles. To verify the output save it to an image file
and look at it that way.
Valid attributes
----------------
- dot styles, passed via the :py:meth:`Dot.style` method::
rankdir = 'LR' (draws the graph horizontally, left to right)
ranksep = number (rank separation in inches)
- node attributes, passed via the :py:meth:`Dot.node_style` method::
style = 'filled' | 'invisible' | 'diagonals' | 'rounded'
shape = 'box' | 'ellipse' | 'circle' | 'point' | 'triangle'
- edge attributes, passed via the :py:meth:`Dot.edge_style` method::
style = 'dashed' | 'dotted' | 'solid' | 'invis' | 'bold'
arrowhead = 'box' | 'crow' | 'diamond' | 'dot' | 'inv' | 'none'
| 'tee' | 'vee'
weight = number (the larger the number the closer the nodes will be)
- valid `graphviz colors
`_
- for more details on how to control the graph drawing process see the
`graphviz reference
`_.
"""
import os
import warnings
from altgraph import GraphError
class Dot(object):
"""
A class providing a **graphviz** (dot language) representation
allowing a fine grained control over how the graph is being
displayed.
If the :command:`dot` and :command:`dotty` programs are not in the current
system path their location needs to be specified in the contructor.
"""
def __init__(
self,
graph=None,
nodes=None,
edgefn=None,
nodevisitor=None,
edgevisitor=None,
name="G",
dot="dot",
dotty="dotty",
neato="neato",
graphtype="digraph",
):
"""
Initialization.
"""
self.name, self.attr = name, {}
assert graphtype in ["graph", "digraph"]
self.type = graphtype
self.temp_dot = "tmp_dot.dot"
self.temp_neo = "tmp_neo.dot"
self.dot, self.dotty, self.neato = dot, dotty, neato
# self.nodes: node styles
# self.edges: edge styles
self.nodes, self.edges = {}, {}
if graph is not None and nodes is None:
nodes = graph
if graph is not None and edgefn is None:
def edgefn(node, graph=graph):
return graph.out_nbrs(node)
if nodes is None:
nodes = ()
seen = set()
for node in nodes:
if nodevisitor is None:
style = {}
else:
style = nodevisitor(node)
if style is not None:
self.nodes[node] = {}
self.node_style(node, **style)
seen.add(node)
if edgefn is not None:
for head in seen:
for tail in (n for n in edgefn(head) if n in seen):
if edgevisitor is None:
edgestyle = {}
else:
edgestyle = edgevisitor(head, tail)
if edgestyle is not None:
if head not in self.edges:
self.edges[head] = {}
self.edges[head][tail] = {}
self.edge_style(head, tail, **edgestyle)
def style(self, **attr):
"""
Changes the overall style
"""
self.attr = attr
def display(self, mode="dot"):
"""
Displays the current graph via dotty
"""
if mode == "neato":
self.save_dot(self.temp_neo)
neato_cmd = "%s -o %s %s" % (self.neato, self.temp_dot, self.temp_neo)
os.system(neato_cmd)
else:
self.save_dot(self.temp_dot)
plot_cmd = "%s %s" % (self.dotty, self.temp_dot)
os.system(plot_cmd)
def node_style(self, node, **kwargs):
"""
Modifies a node style to the dot representation.
"""
if node not in self.edges:
self.edges[node] = {}
self.nodes[node] = kwargs
def all_node_style(self, **kwargs):
"""
Modifies all node styles
"""
for node in self.nodes:
self.node_style(node, **kwargs)
def edge_style(self, head, tail, **kwargs):
"""
Modifies an edge style to the dot representation.
"""
if tail not in self.nodes:
raise GraphError("invalid node %s" % (tail,))
try:
if tail not in self.edges[head]:
self.edges[head][tail] = {}
self.edges[head][tail] = kwargs
except KeyError:
raise GraphError("invalid edge %s -> %s " % (head, tail))
def iterdot(self):
# write graph title
if self.type == "digraph":
yield "digraph %s {\n" % (self.name,)
elif self.type == "graph":
yield "graph %s {\n" % (self.name,)
else:
raise GraphError("unsupported graphtype %s" % (self.type,))
# write overall graph attributes
for attr_name, attr_value in sorted(self.attr.items()):
yield '%s="%s";' % (attr_name, attr_value)
yield "\n"
# some reusable patterns
cpatt = '%s="%s",' # to separate attributes
epatt = "];\n" # to end attributes
# write node attributes
for node_name, node_attr in sorted(self.nodes.items()):
yield '\t"%s" [' % (node_name,)
for attr_name, attr_value in sorted(node_attr.items()):
yield cpatt % (attr_name, attr_value)
yield epatt
# write edge attributes
for head in sorted(self.edges):
for tail in sorted(self.edges[head]):
if self.type == "digraph":
yield '\t"%s" -> "%s" [' % (head, tail)
else:
yield '\t"%s" -- "%s" [' % (head, tail)
for attr_name, attr_value in sorted(self.edges[head][tail].items()):
yield cpatt % (attr_name, attr_value)
yield epatt
# finish file
yield "}\n"
def __iter__(self):
return self.iterdot()
def save_dot(self, file_name=None):
"""
Saves the current graph representation into a file
"""
if not file_name:
warnings.warn(DeprecationWarning, "always pass a file_name")
file_name = self.temp_dot
with open(file_name, "w") as fp:
for chunk in self.iterdot():
fp.write(chunk)
def save_img(self, file_name=None, file_type="gif", mode="dot"):
"""
Saves the dot file as an image file
"""
if not file_name:
warnings.warn(DeprecationWarning, "always pass a file_name")
file_name = "out"
if mode == "neato":
self.save_dot(self.temp_neo)
neato_cmd = "%s -o %s %s" % (self.neato, self.temp_dot, self.temp_neo)
os.system(neato_cmd)
plot_cmd = self.dot
else:
self.save_dot(self.temp_dot)
plot_cmd = self.dot
file_name = "%s.%s" % (file_name, file_type)
create_cmd = "%s -T%s %s -o %s" % (
plot_cmd,
file_type,
self.temp_dot,
file_name,
)
os.system(create_cmd)