17bf3db06a
Remove line containing comment - # vim: tabstop=4 shiftwidth=4 softtabstop=4 Change-Id: I7581cc88b8de433d5609ed06c6570b0b45c13573 Closes-Bug:#1229324
99 lines
3.5 KiB
Python
99 lines
3.5 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import networkx as nx
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import six
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def get_edge_attrs(graph, u, v):
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"""Gets the dictionary of edge attributes between u->v (or none)."""
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if not graph.has_edge(u, v):
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return None
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return dict(graph.adj[u][v])
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def merge_graphs(graphs, allow_overlaps=False):
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if not graphs:
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return None
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graph = graphs[0]
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for g in graphs[1:]:
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# This should ensure that the nodes to be merged do not already exist
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# in the graph that is to be merged into. This could be problematic if
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# there are duplicates.
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if not allow_overlaps:
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# Attempt to induce a subgraph using the to be merged graphs nodes
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# and see if any graph results.
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overlaps = graph.subgraph(g.nodes_iter())
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if len(overlaps):
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raise ValueError("Can not merge graph %s into %s since there "
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"are %s overlapping nodes" (g, graph,
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len(overlaps)))
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# Keep the target graphs name.
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name = graph.name
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graph = nx.algorithms.compose(graph, g)
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graph.name = name
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return graph
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def get_no_successors(graph):
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"""Returns an iterator for all nodes with no successors."""
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for n in graph.nodes_iter():
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if not len(graph.successors(n)):
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yield n
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def get_no_predecessors(graph):
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"""Returns an iterator for all nodes with no predecessors."""
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for n in graph.nodes_iter():
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if not len(graph.predecessors(n)):
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yield n
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def pformat(graph):
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"""Pretty formats your graph into a string representation that includes
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details about your graph, including; name, type, frozeness, node count,
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nodes, edge count, edges, graph density and graph cycles (if any).
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"""
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lines = []
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lines.append("Name: %s" % graph.name)
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lines.append("Type: %s" % type(graph).__name__)
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lines.append("Frozen: %s" % nx.is_frozen(graph))
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lines.append("Nodes: %s" % graph.number_of_nodes())
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for n in graph.nodes_iter():
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lines.append(" - %s" % n)
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lines.append("Edges: %s" % graph.number_of_edges())
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for (u, v, e_data) in graph.edges_iter(data=True):
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if e_data:
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lines.append(" %s -> %s (%s)" % (u, v, e_data))
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else:
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lines.append(" %s -> %s" % (u, v))
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lines.append("Density: %0.3f" % nx.density(graph))
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cycles = list(nx.cycles.recursive_simple_cycles(graph))
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lines.append("Cycles: %s" % len(cycles))
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for cycle in cycles:
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buf = six.StringIO()
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buf.write(str(cycle[0]))
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for i in range(1, len(cycle)):
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buf.write(" --> %s" % (cycle[i]))
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buf.write(" --> %s" % (cycle[0]))
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lines.append(" %s" % buf.getvalue())
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return "\n".join(lines)
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def export_graph_to_dot(graph):
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"""Exports the graph to a dot format (requires pydot library)."""
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return nx.to_pydot(graph).to_string()
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