355 lines
9.7 KiB
Python
355 lines
9.7 KiB
Python
|
"""
|
||
|
*****
|
||
|
Pydot
|
||
|
*****
|
||
|
|
||
|
Import and export NetworkX graphs in Graphviz dot format using pydot.
|
||
|
|
||
|
Either this module or nx_agraph can be used to interface with graphviz.
|
||
|
|
||
|
See Also
|
||
|
--------
|
||
|
pydot: https://github.com/erocarrera/pydot
|
||
|
Graphviz: https://www.graphviz.org
|
||
|
DOT Language: http://www.graphviz.org/doc/info/lang.html
|
||
|
"""
|
||
|
# Author: Aric Hagberg (aric.hagberg@gmail.com)
|
||
|
|
||
|
# Copyright (C) 2004-2019 by
|
||
|
# Aric Hagberg <hagberg@lanl.gov>
|
||
|
# Dan Schult <dschult@colgate.edu>
|
||
|
# Pieter Swart <swart@lanl.gov>
|
||
|
# Cecil Curry <leycec@gmail.com>
|
||
|
# All rights reserved.
|
||
|
# BSD license.
|
||
|
from locale import getpreferredencoding
|
||
|
from networkx.utils import open_file, make_str
|
||
|
import networkx as nx
|
||
|
|
||
|
__all__ = ['write_dot', 'read_dot', 'graphviz_layout', 'pydot_layout',
|
||
|
'to_pydot', 'from_pydot']
|
||
|
|
||
|
# 2.x/3.x compatibility
|
||
|
try:
|
||
|
basestring
|
||
|
except NameError:
|
||
|
basestring = str
|
||
|
unicode = str
|
||
|
|
||
|
|
||
|
@open_file(1, mode='w')
|
||
|
def write_dot(G, path):
|
||
|
"""Write NetworkX graph G to Graphviz dot format on path.
|
||
|
|
||
|
Path can be a string or a file handle.
|
||
|
"""
|
||
|
P = to_pydot(G)
|
||
|
path.write(P.to_string())
|
||
|
return
|
||
|
|
||
|
|
||
|
@open_file(0, mode='r')
|
||
|
def read_dot(path):
|
||
|
"""Returns a NetworkX :class:`MultiGraph` or :class:`MultiDiGraph` from the
|
||
|
dot file with the passed path.
|
||
|
|
||
|
If this file contains multiple graphs, only the first such graph is
|
||
|
returned. All graphs _except_ the first are silently ignored.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
path : str or file
|
||
|
Filename or file handle.
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
G : MultiGraph or MultiDiGraph
|
||
|
A :class:`MultiGraph` or :class:`MultiDiGraph`.
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
Use `G = nx.Graph(read_dot(path))` to return a :class:`Graph` instead of a
|
||
|
:class:`MultiGraph`.
|
||
|
"""
|
||
|
import pydot
|
||
|
data = path.read()
|
||
|
|
||
|
# List of one or more "pydot.Dot" instances deserialized from this file.
|
||
|
P_list = pydot.graph_from_dot_data(data)
|
||
|
|
||
|
# Convert only the first such instance into a NetworkX graph.
|
||
|
return from_pydot(P_list[0])
|
||
|
|
||
|
|
||
|
def from_pydot(P):
|
||
|
"""Returns a NetworkX graph from a Pydot graph.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
P : Pydot graph
|
||
|
A graph created with Pydot
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
G : NetworkX multigraph
|
||
|
A MultiGraph or MultiDiGraph.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> K5 = nx.complete_graph(5)
|
||
|
>>> A = nx.nx_pydot.to_pydot(K5)
|
||
|
>>> G = nx.nx_pydot.from_pydot(A) # return MultiGraph
|
||
|
|
||
|
# make a Graph instead of MultiGraph
|
||
|
>>> G = nx.Graph(nx.nx_pydot.from_pydot(A))
|
||
|
|
||
|
"""
|
||
|
if P.get_strict(None): # pydot bug: get_strict() shouldn't take argument
|
||
|
multiedges = False
|
||
|
else:
|
||
|
multiedges = True
|
||
|
|
||
|
if P.get_type() == 'graph': # undirected
|
||
|
if multiedges:
|
||
|
N = nx.MultiGraph()
|
||
|
else:
|
||
|
N = nx.Graph()
|
||
|
else:
|
||
|
if multiedges:
|
||
|
N = nx.MultiDiGraph()
|
||
|
else:
|
||
|
N = nx.DiGraph()
|
||
|
|
||
|
# assign defaults
|
||
|
name = P.get_name().strip('"')
|
||
|
if name != '':
|
||
|
N.name = name
|
||
|
|
||
|
# add nodes, attributes to N.node_attr
|
||
|
for p in P.get_node_list():
|
||
|
n = p.get_name().strip('"')
|
||
|
if n in ('node', 'graph', 'edge'):
|
||
|
continue
|
||
|
N.add_node(n, **p.get_attributes())
|
||
|
|
||
|
# add edges
|
||
|
for e in P.get_edge_list():
|
||
|
u = e.get_source()
|
||
|
v = e.get_destination()
|
||
|
attr = e.get_attributes()
|
||
|
s = []
|
||
|
d = []
|
||
|
|
||
|
if isinstance(u, basestring):
|
||
|
s.append(u.strip('"'))
|
||
|
else:
|
||
|
for unodes in u['nodes']:
|
||
|
s.append(unodes.strip('"'))
|
||
|
|
||
|
if isinstance(v, basestring):
|
||
|
d.append(v.strip('"'))
|
||
|
else:
|
||
|
for vnodes in v['nodes']:
|
||
|
d.append(vnodes.strip('"'))
|
||
|
|
||
|
for source_node in s:
|
||
|
for destination_node in d:
|
||
|
N.add_edge(source_node, destination_node, **attr)
|
||
|
|
||
|
# add default attributes for graph, nodes, edges
|
||
|
pattr = P.get_attributes()
|
||
|
if pattr:
|
||
|
N.graph['graph'] = pattr
|
||
|
try:
|
||
|
N.graph['node'] = P.get_node_defaults()[0]
|
||
|
except (IndexError, TypeError):
|
||
|
pass # N.graph['node']={}
|
||
|
try:
|
||
|
N.graph['edge'] = P.get_edge_defaults()[0]
|
||
|
except (IndexError, TypeError):
|
||
|
pass # N.graph['edge']={}
|
||
|
return N
|
||
|
|
||
|
|
||
|
def to_pydot(N):
|
||
|
"""Returns a pydot graph from a NetworkX graph N.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
N : NetworkX graph
|
||
|
A graph created with NetworkX
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> K5 = nx.complete_graph(5)
|
||
|
>>> P = nx.nx_pydot.to_pydot(K5)
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
|
||
|
"""
|
||
|
import pydot
|
||
|
|
||
|
# set Graphviz graph type
|
||
|
if N.is_directed():
|
||
|
graph_type = 'digraph'
|
||
|
else:
|
||
|
graph_type = 'graph'
|
||
|
strict = nx.number_of_selfloops(N) == 0 and not N.is_multigraph()
|
||
|
|
||
|
name = N.name
|
||
|
graph_defaults = N.graph.get('graph', {})
|
||
|
if name == '':
|
||
|
P = pydot.Dot('', graph_type=graph_type, strict=strict,
|
||
|
**graph_defaults)
|
||
|
else:
|
||
|
P = pydot.Dot('"%s"' % name, graph_type=graph_type, strict=strict,
|
||
|
**graph_defaults)
|
||
|
try:
|
||
|
P.set_node_defaults(**N.graph['node'])
|
||
|
except KeyError:
|
||
|
pass
|
||
|
try:
|
||
|
P.set_edge_defaults(**N.graph['edge'])
|
||
|
except KeyError:
|
||
|
pass
|
||
|
|
||
|
for n, nodedata in N.nodes(data=True):
|
||
|
str_nodedata = dict((k, make_str(v)) for k, v in nodedata.items())
|
||
|
p = pydot.Node(make_str(n), **str_nodedata)
|
||
|
P.add_node(p)
|
||
|
|
||
|
if N.is_multigraph():
|
||
|
for u, v, key, edgedata in N.edges(data=True, keys=True):
|
||
|
str_edgedata = dict((k, make_str(v)) for k, v in edgedata.items()
|
||
|
if k != 'key')
|
||
|
edge = pydot.Edge(make_str(u), make_str(v),
|
||
|
key=make_str(key), **str_edgedata)
|
||
|
P.add_edge(edge)
|
||
|
|
||
|
else:
|
||
|
for u, v, edgedata in N.edges(data=True):
|
||
|
str_edgedata = dict((k, make_str(v)) for k, v in edgedata.items())
|
||
|
edge = pydot.Edge(make_str(u), make_str(v), **str_edgedata)
|
||
|
P.add_edge(edge)
|
||
|
return P
|
||
|
|
||
|
|
||
|
def graphviz_layout(G, prog='neato', root=None):
|
||
|
"""Create node positions using Pydot and Graphviz.
|
||
|
|
||
|
Returns a dictionary of positions keyed by node.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
G : NetworkX Graph
|
||
|
The graph for which the layout is computed.
|
||
|
prog : string (default: 'neato')
|
||
|
The name of the GraphViz program to use for layout.
|
||
|
Options depend on GraphViz version but may include:
|
||
|
'dot', 'twopi', 'fdp', 'sfdp', 'circo'
|
||
|
root : Node from G or None (default: None)
|
||
|
The node of G from which to start some layout algorithms.
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
Dictionary of (x, y) positions keyed by node.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> G = nx.complete_graph(4)
|
||
|
>>> pos = nx.nx_pydot.graphviz_layout(G)
|
||
|
>>> pos = nx.nx_pydot.graphviz_layout(G, prog='dot')
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
This is a wrapper for pydot_layout.
|
||
|
"""
|
||
|
return pydot_layout(G=G, prog=prog, root=root)
|
||
|
|
||
|
|
||
|
def pydot_layout(G, prog='neato', root=None):
|
||
|
"""Create node positions using :mod:`pydot` and Graphviz.
|
||
|
|
||
|
Parameters
|
||
|
--------
|
||
|
G : Graph
|
||
|
NetworkX graph to be laid out.
|
||
|
prog : string (default: 'neato')
|
||
|
Name of the GraphViz command to use for layout.
|
||
|
Options depend on GraphViz version but may include:
|
||
|
'dot', 'twopi', 'fdp', 'sfdp', 'circo'
|
||
|
root : Node from G or None (default: None)
|
||
|
The node of G from which to start some layout algorithms.
|
||
|
|
||
|
Returns
|
||
|
--------
|
||
|
dict
|
||
|
Dictionary of positions keyed by node.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> G = nx.complete_graph(4)
|
||
|
>>> pos = nx.nx_pydot.pydot_layout(G)
|
||
|
>>> pos = nx.nx_pydot.pydot_layout(G, prog='dot')
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
If you use complex node objects, they may have the same string
|
||
|
representation and GraphViz could treat them as the same node.
|
||
|
The layout may assign both nodes a single location. See Issue #1568
|
||
|
If this occurs in your case, consider relabeling the nodes just
|
||
|
for the layout computation using something similar to:
|
||
|
|
||
|
H = nx.convert_node_labels_to_integers(G, label_attribute='node_label')
|
||
|
H_layout = nx.nx_pydot.pydot_layout(G, prog='dot')
|
||
|
G_layout = {H.nodes[n]['node_label']: p for n, p in H_layout.items()}
|
||
|
|
||
|
"""
|
||
|
import pydot
|
||
|
P = to_pydot(G)
|
||
|
if root is not None:
|
||
|
P.set("root", make_str(root))
|
||
|
|
||
|
# List of low-level bytes comprising a string in the dot language converted
|
||
|
# from the passed graph with the passed external GraphViz command.
|
||
|
D_bytes = P.create_dot(prog=prog)
|
||
|
|
||
|
# Unique string decoded from these bytes with the preferred locale encoding
|
||
|
D = unicode(D_bytes, encoding=getpreferredencoding())
|
||
|
|
||
|
if D == "": # no data returned
|
||
|
print("Graphviz layout with %s failed" % (prog))
|
||
|
print()
|
||
|
print("To debug what happened try:")
|
||
|
print("P = nx.nx_pydot.to_pydot(G)")
|
||
|
print("P.write_dot(\"file.dot\")")
|
||
|
print("And then run %s on file.dot" % (prog))
|
||
|
return
|
||
|
|
||
|
# List of one or more "pydot.Dot" instances deserialized from this string.
|
||
|
Q_list = pydot.graph_from_dot_data(D)
|
||
|
assert len(Q_list) == 1
|
||
|
|
||
|
# The first and only such instance, as guaranteed by the above assertion.
|
||
|
Q = Q_list[0]
|
||
|
|
||
|
node_pos = {}
|
||
|
for n in G.nodes():
|
||
|
pydot_node = pydot.Node(make_str(n)).get_name()
|
||
|
node = Q.get_node(pydot_node)
|
||
|
|
||
|
if isinstance(node, list):
|
||
|
node = node[0]
|
||
|
pos = node.get_pos()[1:-1] # strip leading and trailing double quotes
|
||
|
if pos is not None:
|
||
|
xx, yy = pos.split(",")
|
||
|
node_pos[n] = (float(xx), float(yy))
|
||
|
return node_pos
|
||
|
|
||
|
|
||
|
# fixture for pytest
|
||
|
def setup_module(module):
|
||
|
import pytest
|
||
|
pytdot = pytest.importorskip('pytdot')
|