/usr/share/pyshared/pygraph/classes/digraph.py is in python-pygraph 1.8.2-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 | # Copyright (c) 2007-2009 Pedro Matiello <pmatiello@gmail.com>
# Christian Muise <christian.muise@gmail.com>
# Johannes Reinhardt <jreinhardt@ist-dein-freund.de>
# Nathan Davis <davisn90210@gmail.com>
# Zsolt Haraszti <zsolt@drawwell.net>
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
"""
Digraph class
"""
# Imports
from pygraph.classes.exceptions import AdditionError
from pygraph.mixins.labeling import labeling
from pygraph.mixins.common import common
from pygraph.mixins.basegraph import basegraph
class digraph (basegraph, common, labeling):
"""
Digraph class.
Digraphs are built of nodes and directed edges.
@sort: __eq__, __init__, __ne__, add_edge, add_node, del_edge, del_node, edges, has_edge, has_node,
incidents, neighbors, node_order, nodes
"""
DIRECTED = True
def __init__(self):
"""
Initialize a digraph.
"""
common.__init__(self)
labeling.__init__(self)
self.node_neighbors = {} # Pairing: Node -> Neighbors
self.node_incidence = {} # Pairing: Node -> Incident nodes
def nodes(self):
"""
Return node list.
@rtype: list
@return: Node list.
"""
return list(self.node_neighbors.keys())
def neighbors(self, node):
"""
Return all nodes that are directly accessible from given node.
@type node: node
@param node: Node identifier
@rtype: list
@return: List of nodes directly accessible from given node.
"""
return self.node_neighbors[node]
def incidents(self, node):
"""
Return all nodes that are incident to the given node.
@type node: node
@param node: Node identifier
@rtype: list
@return: List of nodes directly accessible from given node.
"""
return self.node_incidence[node]
def edges(self):
"""
Return all edges in the graph.
@rtype: list
@return: List of all edges in the graph.
"""
return [ a for a in self._edges() ]
def _edges(self):
for n, neighbors in self.node_neighbors.items():
for neighbor in neighbors:
yield (n, neighbor)
def has_node(self, node):
"""
Return whether the requested node exists.
@type node: node
@param node: Node identifier
@rtype: boolean
@return: Truth-value for node existence.
"""
return node in self.node_neighbors
def add_node(self, node, attrs = None):
"""
Add given node to the graph.
@attention: While nodes can be of any type, it's strongly recommended to use only
numbers and single-line strings as node identifiers if you intend to use write().
@type node: node
@param node: Node identifier.
@type attrs: list
@param attrs: List of node attributes specified as (attribute, value) tuples.
"""
if attrs is None:
attrs = []
if (node not in self.node_neighbors):
self.node_neighbors[node] = []
self.node_incidence[node] = []
self.node_attr[node] = attrs
else:
raise AdditionError("Node %s already in digraph" % node)
def add_edge(self, edge, wt = 1, label="", attrs = []):
"""
Add an directed edge to the graph connecting two nodes.
An edge, here, is a pair of nodes like C{(n, m)}.
@type edge: tuple
@param edge: Edge.
@type wt: number
@param wt: Edge weight.
@type label: string
@param label: Edge label.
@type attrs: list
@param attrs: List of node attributes specified as (attribute, value) tuples.
"""
u, v = edge
for n in [u,v]:
if not n in self.node_neighbors:
raise AdditionError( "%s is missing from the node_neighbors table" % n )
if not n in self.node_incidence:
raise AdditionError( "%s is missing from the node_incidence table" % n )
if v in self.node_neighbors[u] and u in self.node_incidence[v]:
raise AdditionError("Edge (%s, %s) already in digraph" % (u, v))
else:
self.node_neighbors[u].append(v)
self.node_incidence[v].append(u)
self.set_edge_weight((u, v), wt)
self.add_edge_attributes( (u, v), attrs )
self.set_edge_properties( (u, v), label=label, weight=wt )
def del_node(self, node):
"""
Remove a node from the graph.
@type node: node
@param node: Node identifier.
"""
for each in list(self.incidents(node)):
# Delete all the edges incident on this node
self.del_edge((each, node))
for each in list(self.neighbors(node)):
# Delete all the edges pointing to this node.
self.del_edge((node, each))
# Remove this node from the neighbors and incidents tables
del(self.node_neighbors[node])
del(self.node_incidence[node])
# Remove any labeling which may exist.
self.del_node_labeling( node )
def del_edge(self, edge):
"""
Remove an directed edge from the graph.
@type edge: tuple
@param edge: Edge.
"""
u, v = edge
self.node_neighbors[u].remove(v)
self.node_incidence[v].remove(u)
self.del_edge_labeling( (u,v) )
def has_edge(self, edge):
"""
Return whether an edge exists.
@type edge: tuple
@param edge: Edge.
@rtype: boolean
@return: Truth-value for edge existence.
"""
u, v = edge
return (u, v) in self.edge_properties
def node_order(self, node):
"""
Return the order of the given node.
@rtype: number
@return: Order of the given node.
"""
return len(self.neighbors(node))
def __eq__(self, other):
"""
Return whether this graph is equal to another one.
@type other: graph, digraph
@param other: Other graph or digraph
@rtype: boolean
@return: Whether this graph and the other are equal.
"""
return common.__eq__(self, other) and labeling.__eq__(self, other)
def __ne__(self, other):
"""
Return whether this graph is not equal to another one.
@type other: graph, digraph
@param other: Other graph or digraph
@rtype: boolean
@return: Whether this graph and the other are different.
"""
return not (self == other)
|