# vim:ts=4:sw=4:sts=4:et
# -*- coding: utf-8 -*-
"""Summary representation of a graph.
@undocumented: _get_wrapper_for_width, FakeWrapper
"""
from igraph.vendor import vendor_import
from igraph.statistics import median
from itertools import islice
from math import ceil
from textwrap import TextWrapper
__all__ = ["GraphSummary"]
__license__ = u"""\
Copyright (C) 2006-2012 Tamás Nepusz <ntamas@gmail.com>
Pázmány Péter sétány 1/a, 1117 Budapest, Hungary
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
"""
texttable = vendor_import("texttable")
class FakeWrapper(object):
"""Object whose interface is compatible with C{textwrap.TextWrapper}
but does no wrapping."""
def __init__(self, *args, **kwds):
pass
def fill(self, text):
return [text]
def wrap(self, text):
return [text]
def _get_wrapper_for_width(width, *args, **kwds):
"""Returns a text wrapper that wraps text for the given width.
@param width: the maximal width of each line that the text wrapper
produces. C{None} means that no wrapping will be performed.
"""
if width is None:
return FakeWrapper(*args, **kwds)
return TextWrapper(width=width, *args, **kwds)
class GraphSummary(object):
"""Summary representation of a graph.
The summary representation includes a header line and the list of
edges. The header line consists of C{IGRAPH}, followed by a
four-character long code, the number of vertices, the number of
edges, two dashes (C{--}) and the name of the graph (i.e.
the contents of the C{name} attribute, if any). For instance,
a header line may look like this::
IGRAPH U--- 4 5 --
The four-character code describes some basic properties of the
graph. The first character is C{U} if the graph is undirected,
C{D} if it is directed. The second letter is C{N} if the graph
has a vertex attribute called C{name}, or a dash otherwise. The
third letter is C{W} if the graph is weighted (i.e. it has an
edge attribute called C{weight}), or a dash otherwise. The
fourth letter is C{B} if the graph has a vertex attribute called
C{type}; this is usually used for bipartite graphs.
Edges may be presented as an ordinary edge list or an adjacency
list. By default, this depends on the number of edges; however,
you can control it with the appropriate constructor arguments.
@undocumented: _construct_edgelist_adjlist, _construct_edgelist_compressed,
_construct_edgelist_edgelist, _construct_graph_attributes,
_construct_vertex_attributes, _construct_header, _edge_attribute_iterator,
_infer_column_alignment, _new_table, _vertex_attribute_iterator
"""
def __init__(self, graph, verbosity=0, width=78,
edge_list_format="auto",
max_rows=99999,
print_graph_attributes=False,
print_vertex_attributes=False,
print_edge_attributes=False,
full=False):
"""Constructs a summary representation of a graph.
@param verbosity: the verbosity of the summary. If zero, only
the header line will be returned. If one, the header line
and the list of edges will both be returned.
@param width: the maximal width of each line in the summary.
C{None} means that no limit will be enforced.
@param max_rows: the maximal number of rows to print in a single
table (e.g., vertex attribute table or edge attribute table)
@param edge_list_format: format of the edge list in the summary.
Supported formats are: C{compressed}, C{adjlist}, C{edgelist},
C{auto}, which selects automatically from the other three based
on some simple criteria.
@param print_graph_attributes: whether to print graph attributes
if there are any.
@param print_vertex_attributes: whether to print vertex attributes
if there are any.
@param print_edge_attributes: whether to print edge attributes
if there are any.
@param full: False has no effect; True turns on the attribute
printing for graph, vertex and edge attributes with verbosity 1.
"""
if full:
print_graph_attributes = True
print_vertex_attributes = True
print_edge_attributes = True
verbosity = max(verbosity, 1)
self._graph = graph
self.edge_list_format = edge_list_format.lower()
self.max_rows = int(max_rows)
self.print_graph_attributes = print_graph_attributes
self.print_vertex_attributes = print_vertex_attributes
self.print_edge_attributes = print_edge_attributes
self.verbosity = verbosity
self.width = width
self.wrapper = _get_wrapper_for_width(self.width,
break_on_hyphens=False)
if self._graph.is_named():
self._edges_header = "+ edges (vertex names):"
else:
self._edges_header = "+ edges:"
self._arrow = ["--", "->"][self._graph.is_directed()]
self._arrow_format = "%%s%s%%s" % self._arrow
def _construct_edgelist_adjlist(self):
"""Constructs the part in the summary that prints the edge list in an
adjacency list format."""
result = [self._edges_header]
arrow = self._arrow_format
if self._graph.vcount() == 0:
return
if self._graph.is_named():
names = self._graph.vs["name"]
maxlen = max(len(name) for name in names)
format_str = "%%%ds %s %%s" % (maxlen, self._arrow)
for v1, name in enumerate(names):
neis = self._graph.successors(v1)
neis = ", ".join(str(names[v2]) for v2 in neis)
result.append(format_str % (name, neis))
else:
maxlen = len(str(self._graph.vcount()))
num_format = "%%%dd" % maxlen
format_str = "%s %s %%s" % (num_format, self._arrow)
for v1 in xrange(self._graph.vcount()):
neis = self._graph.successors(v1)
neis = " ".join(num_format % v2 for v2 in neis)
result.append(format_str % (v1, neis))
# Try to wrap into multiple columns if that works with the given width
if self.width is not None:
maxlen = max(len(line) for line in result[1:])
colcount = int(self.width + 3) / int(maxlen + 3)
if colcount > 1:
# Rewrap to multiple columns
nrows = len(result) - 1
colheight = int(ceil(nrows / float(colcount)))
newrows = [[] for _ in xrange(colheight)]
for i, row in enumerate(result[1:]):
newrows[i % colheight].append(row.ljust(maxlen))
result[1:] = [" ".join(row) for row in newrows]
return result
def _construct_edgelist_compressed(self):
"""Constructs the part in the summary that prints the edge list in a
compressed format suitable for graphs with mostly small degrees."""
result = [self._edges_header]
arrow = self._arrow_format
if self._graph.is_named():
names = self._graph.vs["name"]
edges = ", ".join(arrow % (names[edge.source], names[edge.target])
for edge in self._graph.es)
else:
edges = " ".join(arrow % edge.tuple for edge in self._graph.es)
result.append(edges)
return result
def _construct_edgelist_edgelist(self):
"""Constructs the part in the summary that prints the edge list in a
full edge list format."""
attrs = sorted(self._graph.edge_attributes())
table = self._new_table(headers=["", "edge"] + attrs)
table.add_rows(islice(self._edge_attribute_iterator(attrs), 0, self.max_rows),
header=False)
table.set_cols_align(["l", "l"] + self._infer_column_alignment(edge_attrs=attrs))
result = [self._edges_header]
result.extend(table.draw().split("\n"))
return result
def _construct_graph_attributes(self):
"""Constructs the part in the summary that lists the graph attributes."""
attrs = self._graph.attributes()
if not attrs:
return []
result = ["+ graph attributes:"]
attrs.sort()
for attr in attrs:
result.append("[[%s]]" % (attr, ))
result.append(str(self._graph[attr]))
return result
def _construct_vertex_attributes(self):
"""Constructs the part in the summary that lists the vertex attributes."""
attrs = sorted(self._graph.vertex_attributes())
if not attrs or (len(attrs) == 1 and "name" in attrs):
return []
table = self._new_table(headers=[""] + attrs)
table.add_rows(islice(self._vertex_attribute_iterator(attrs), 0, self.max_rows),
header=False)
table.set_cols_align(["l"] + self._infer_column_alignment(vertex_attrs=attrs))
result = ["+ vertex attributes:"]
result.extend(table.draw().split("\n"))
return result
def _construct_header(self):
"""Constructs the header part of the summary."""
graph = self._graph
params = dict(
directed="UD"[graph.is_directed()],
named="-N"[graph.is_named()],
weighted="-W"[graph.is_weighted()],
typed="-T"["type" in graph.vertex_attributes()],
vcount=graph.vcount(),
ecount=graph.ecount(),
)
if "name" in graph.attributes():
params["name"] = graph["name"]
else:
params["name"] = ""
result = ["IGRAPH %(directed)s%(named)s%(weighted)s%(typed)s "\
"%(vcount)d %(ecount)d -- %(name)s" % params]
attrs = ["%s (g)" % (name, ) for name in sorted(graph.attributes())]
attrs.extend("%s (v)" % (name, ) for name in sorted(graph.vertex_attributes()))
attrs.extend("%s (e)" % (name, ) for name in sorted(graph.edge_attributes()))
if attrs:
result.append("+ attr: %s" % ", ".join(attrs))
if self.wrapper is not None:
self.wrapper.subsequent_indent = ' '
result[-1:] = self.wrapper.wrap(result[-1])
self.wrapper.subsequent_indent = ''
return result
def _edge_attribute_iterator(self, attribute_order):
"""Returns an iterator that yields the rows of the edge attribute table
in the summary. `attribute_order` must be a list containing the names of
the attributes to be presented in this table."""
arrow = self._arrow_format
if self._graph.is_named():
names = self._graph.vs["name"]
for edge in self._graph.es:
formatted_edge = arrow % (names[edge.source], names[edge.target])
yield ["[%d]" % edge.index, formatted_edge] + \
[edge[attr] for attr in attribute_order]
else:
for edge in self._graph.es:
formatted_edge = arrow % edge.tuple
yield ["[%d]" % edge.index, formatted_edge] + \
[edge[attr] for attr in attribute_order]
def _infer_column_alignment(self, vertex_attrs=None, edge_attrs=None):
"""Infers the preferred alignment for the given vertex and edge attributes
in the tables by peeking into the attribute values of the first 100 vertices
or edges. Numeric attributes will be aligned right, everything else will be
aligned left."""
values = []
if vertex_attrs is not None:
vs = self._graph.vs[:100]
values.extend(vs[attr] for attr in vertex_attrs)
if edge_attrs is not None:
es = self._graph.es[:100]
values.extend(es[attr] for attr in edge_attrs)
result = []
for vs in values:
is_numeric = True
try:
[float(x) for x in vs]
except ValueError:
is_numeric = False
if is_numeric:
result.append("r")
else:
result.append("l")
return result
def _new_table(self, headers=None):
"""Constructs a new table to pretty-print vertex and edge attributes"""
table = texttable.Texttable(max_width=0)
table.set_deco(0)
if headers is not None:
table.header(headers)
return table
def _vertex_attribute_iterator(self, attribute_order):
"""Returns an iterator that yields the rows of the vertex attribute table
in the summary. `attribute_order` must be a list containing the names of
the attributes to be presented in this table."""
for vertex in self._graph.vs:
yield ["[%d]" % vertex.index] + [vertex[attr] for attr in attribute_order]
def __str__(self):
"""Returns the summary representation as a string."""
output = self._construct_header()
if self.print_graph_attributes:
output.extend(self._construct_graph_attributes())
if self.print_vertex_attributes:
output.extend(self._construct_vertex_attributes())
if self.verbosity <= 0:
return "\n".join(output)
if self._graph.ecount() > 0:
# Add the edge list
if self.edge_list_format == "auto":
if (self.print_edge_attributes and self._graph.edge_attributes()):
format = "edgelist"
elif median(self._graph.degree(mode="out")) < 3:
format = "compressed"
else:
format = "adjlist"
else:
format = self.edge_list_format
method_name = "_construct_edgelist_%s" % format
if hasattr(self, method_name):
output.extend(getattr(self, method_name)())
if self.wrapper is not None:
return "\n".join("\n".join(self.wrapper.wrap(line)) for line in output)
return "\n".join(output)