Ported examples/graph for Python 3. Refs #384

--HG--
extra : convert_revision : svn%3A3ed01bd8-26fb-0310-9e4c-ca1a4053419f/networkx/trunk%401856

12 files changed, 93 insertions, 90 deletions

diff --git a/examples/graph/atlas.py b/examples/graph/atlas.py
index 73231c3a..7aca6cb8 100644
--- a/examples/graph/atlas.py
+++ b/examples/graph/atlas.py
@@ -58,9 +58,9 @@ if __name__ == '__main__':
 
     G=atlas6()
 
-    print "graph has %d nodes with %d edges"\
-          %(nx.number_of_nodes(G),nx.number_of_edges(G))
-    print nx.number_connected_components(G),"connected components"
+    print("graph has %d nodes with %d edges"\
+          %(nx.number_of_nodes(G),nx.number_of_edges(G)))
+    print(nx.number_connected_components(G),"connected components")
 
 
     try:
diff --git a/examples/graph/atlas2.py b/examples/graph/atlas2.py
index bae417a3..1c68540a 100644
--- a/examples/graph/atlas2.py
+++ b/examples/graph/atlas2.py
@@ -23,8 +23,8 @@ atlas=graph_atlas_g()[0:20]
 
 
 for G in atlas:
-    print "graph %s has %d nodes with %d edges"\
-          %(G.name,NX.number_of_nodes(G),NX.number_of_edges(G))
+    print("graph %s has %d nodes with %d edges"
+          %(G.name,NX.number_of_nodes(G),NX.number_of_edges(G)))
     A=NX.to_agraph(G)
     A.graph_attr['label']=G.name 
     # set default node attributes
diff --git a/examples/graph/degree_sequence.py b/examples/graph/degree_sequence.py
index 1c7cb208..e4694ed8 100644
--- a/examples/graph/degree_sequence.py
+++ b/examples/graph/degree_sequence.py
@@ -19,19 +19,19 @@ from networkx.generators.degree_seq import *
 z=[5,3,3,3,3,2,2,2,1,1,1]
 is_valid_degree_sequence(z)
 
-print "Configuration model"
+print("Configuration model")
 G=configuration_model(z)  # configuration model
-degree_sequence=degree(G).values() # degree sequence
-print "Degree sequence", degree_sequence
-print "Degree histogram"
+degree_sequence=list(degree(G).values()) # degree sequence
+print("Degree sequence %s" % degree_sequence)
+print("Degree histogram")
 hist={}
 for d in degree_sequence:
-    if hist.has_key(d):
+    if d in hist:
         hist[d]+=1
     else:
         hist[d]=1
-print "degree #nodes"
+print("degree #nodes")
 for d in hist:
-    print d,hist[d]
+    print('%d %d' % (d,hist[d]))
 
 
diff --git a/examples/graph/erdos_renyi.py b/examples/graph/erdos_renyi.py
index da46f95c..3ac9f7ea 100644
--- a/examples/graph/erdos_renyi.py
+++ b/examples/graph/erdos_renyi.py
@@ -26,10 +26,13 @@ m=20 # 20 edges
 G=gnm_random_graph(n,m)
 
 # some properties
-print "node degree clustering"
+print("node degree clustering")
 for v in nodes(G):
-    print v,degree(G,v),clustering(G,v)
+    print('%s %d %f' % (v,degree(G,v),clustering(G,v)))
 
 # print the adjacency list to terminal 
-write_adjlist(G,sys.stdout)
+try:
+    write_adjlist(G,sys.stdout)
+except TypeError: # Python 3.x
+    write_adjlist(G,sys.stdout.buffer)
 
diff --git a/examples/graph/expected_degree_sequence.py b/examples/graph/expected_degree_sequence.py
index d86dd9b2..de0ebab1 100644
--- a/examples/graph/expected_degree_sequence.py
+++ b/examples/graph/expected_degree_sequence.py
@@ -18,11 +18,11 @@ n=500 # n nodes
 p=0.1
 w=[p*n for i in range(n)] # w = p*n for all nodes
 G=expected_degree_graph(w)  # configuration model
-print "Degree histogram"
-print "degree (#nodes) ****"
+print("Degree histogram")
+print("degree (#nodes) ****")
 dh=degree_histogram(G)
 low=min(degree(G))
 for i in range(low,len(dh)):
     bar=''.join(dh[i]*['*'])
-    print "%2s (%2s) %s"%(i,dh[i],bar)
+    print("%2s (%2s) %s"%(i,dh[i],bar))
 
diff --git a/examples/graph/football.py b/examples/graph/football.py
index 95326814..8028fb2b 100644
--- a/examples/graph/football.py
+++ b/examples/graph/football.py
@@ -19,29 +19,32 @@ __author__ = """Aric Hagberg (hagberg@lanl.gov)"""
 
 try:
     import pyparsing
-except ImportError,e:
+except ImportError as e:
     raise ImportError(str(e)+". Check http://pyparsing.wikispaces.com/")
     
 from networkx import *
 
 url="http://www-personal.umich.edu/~mejn/netdata/football.zip"
 
-import urllib
-import StringIO
+try: # Python 3.x
+    import urllib.request as urllib
+except ImportError: # Python 2.x
+    import urllib
+import io
 import zipfile
 
 sock = urllib.urlopen(url)  # open URL
-s=StringIO.StringIO(sock.read()) # read into StringIO "file"
+s=io.BytesIO(sock.read()) # read into BytesIO "file"
 sock.close()
 
 zf = zipfile.ZipFile(s) # zipfile object
-txt=zf.read('football.txt') # read info file
-gml=zf.read('football.gml') # read gml data
+txt=zf.read('football.txt').decode() # read info file
+gml=zf.read('football.gml').decode() # read gml data
 # throw away bogus first line with # from mejn files
 gml=gml.split('\n')[1:]
 G=parse_gml(gml) # parse gml data
 
-print txt
+print(txt)
 # print degree for each team - number of games
 for n,d in G.degree_iter():
-    print n,d
+    print('%s %d' % (n, d))
diff --git a/examples/graph/karate_club.py b/examples/graph/karate_club.py
index f401b59a..2933aaeb 100644
--- a/examples/graph/karate_club.py
+++ b/examples/graph/karate_club.py
@@ -68,8 +68,8 @@ def karate_graph(create_using=None, **kwds):
 
 
     row=0
-    for line in string.split(zacharydat,'\n'):
-        thisrow=map(int,string.split(line,' '))
+    for line in zacharydat.split('\n'):
+        thisrow=list(map(int,line.split(' ')))
         for col in range(0,len(thisrow)):
             if thisrow[col]==1:
                 G.add_edge(row,col) # col goes from 0,33
@@ -79,6 +79,6 @@ def karate_graph(create_using=None, **kwds):
 if __name__ == "__main__":
 
     G=karate_graph()
-    print "Node Degree"
+    print("Node Degree")
     for v in G:
-        print v,G.degree(v)
+        print('%s %s' % (v,G.degree(v)))
diff --git a/examples/graph/knuth_miles.py b/examples/graph/knuth_miles.py
index 4c5b50e9..11c1ddc1 100644
--- a/examples/graph/knuth_miles.py
+++ b/examples/graph/knuth_miles.py
@@ -34,11 +34,8 @@ def miles_graph():
         from the Stanford GraphBase.
     """
     # open file miles_dat.txt.gz (or miles_dat.txt)
-    try:
-        import gzip
-        fh = gzip.open('knuth_miles.txt.gz','r')
-    except:
-        fh=open("knuth_miles.txt","r")
+    import gzip
+    fh = gzip.open('knuth_miles.txt.gz','r')
 
     G=nx.Graph()
     G.position={}
@@ -46,6 +43,7 @@ def miles_graph():
 
     cities=[]
     for line in fh.readlines():
+        line = line.decode()
         if line.startswith("*"): # skip comments
             continue
 
@@ -76,9 +74,9 @@ if __name__ == '__main__':
 
     G=miles_graph()
 
-    print "Loaded miles_dat.txt containing 128 cities."
-    print "digraph has %d nodes with %d edges"\
-          %(nx.number_of_nodes(G),nx.number_of_edges(G))
+    print("Loaded miles_dat.txt containing 128 cities.")
+    print("digraph has %d nodes with %d edges"\
+          %(nx.number_of_nodes(G),nx.number_of_edges(G)))
 
 
     # make new graph of cites, edge if less then 300 miles between them
diff --git a/examples/graph/napoleon_russian_campaign.py b/examples/graph/napoleon_russian_campaign.py
index 8dd9053d..d9ee0afb 100644
--- a/examples/graph/napoleon_russian_campaign.py
+++ b/examples/graph/napoleon_russian_campaign.py
@@ -12,7 +12,6 @@ __author__ = """Aric Hagberg (hagberg@lanl.gov)"""
 #    All rights reserved.
 #    BSD license.
 
-import matplotlib.pyplot as plt
 import string
 import networkx as nx
 
@@ -94,8 +93,8 @@ def minard_graph():
 36.5,55.0,Malo-Jarosewii"""
 
     c={}
-    for line in string.split(cities,'\n'):
-        x,y,name=string.split(line,',')
+    for line in cities.split('\n'):
+        x,y,name=line.split(',')
         c[name]=(float(x),float(y))
 
     g=[]        
@@ -106,14 +105,14 @@ def minard_graph():
         G.pos={} # location
         G.pop={} # size
         last=None
-        for line in string.split(data,'\n'):
-            x,y,p,r,n=string.split(line,',')
+        for line in data.split('\n'):
+            x,y,p,r,n=line.split(',')
             G.pos[i]=(float(x),float(y))
             G.pop[i]=int(p)
             if last is None:
                 last=i
             else:
-                G.add_edge(i,last,(r,int(n)))
+                G.add_edge(i,last,{r:int(n)})
                 last=i
             i=i+1
         g.append(G)        
@@ -124,18 +123,22 @@ if __name__ == "__main__":
 
     (g,city)=minard_graph()
 
-    plt.figure(1,figsize=(11,5))
-    plt.clf()
-    colors=['b','g','r']
-    for G in g:
-        c=colors.pop(0)
-        node_size=[int(G.pop[n]/300.0) for n in G]
-        nx.draw_networkx_edges(G,G.pos,edge_color=c,width=4,alpha=0.5)
-        nx.draw_networkx_nodes(G,G.pos,node_size=node_size,node_color=c,alpha=0.5)
-        nx.draw_networkx_nodes(G,G.pos,node_size=5,node_color='k')
+    try:
+        import matplotlib.pyplot as plt
+        plt.figure(1,figsize=(11,5))
+        plt.clf()
+        colors=['b','g','r']
+        for G in g:
+            c=colors.pop(0)
+            node_size=[int(G.pop[n]/300.0) for n in G]
+            nx.draw_networkx_edges(G,G.pos,edge_color=c,width=4,alpha=0.5)
+            nx.draw_networkx_nodes(G,G.pos,node_size=node_size,node_color=c,alpha=0.5)
+            nx.draw_networkx_nodes(G,G.pos,node_size=5,node_color='k')
 
-    for c in city:
-        x,y=city[c]
-        plt.text(x,y+0.1,c)
-    plt.savefig("napoleon_russian_campaign.png")
+        for c in city:
+            x,y=city[c]
+            plt.text(x,y+0.1,c)
+        plt.savefig("napoleon_russian_campaign.png")
+    except ImportError:
+        pass
 
diff --git a/examples/graph/roget.py b/examples/graph/roget.py
index a6d3526b..be633f92 100644
--- a/examples/graph/roget.py
+++ b/examples/graph/roget.py
@@ -20,6 +20,7 @@ References.
 
 
 """
+from __future__ import print_function
 __author__ = """Brendt Wohlberg\nAric Hagberg (hagberg@lanl.gov)"""
 __date__ = "$Date: 2005-04-01 07:56:22 -0700 (Fri, 01 Apr 2005) $"
 __credits__ = """"""
@@ -40,15 +41,13 @@ def roget_graph():
     the Stanford Graph Base.
     """
     # open file roget_dat.txt.gz (or roget_dat.txt)
-    try:
-        import gzip
-        fh=gzip.open('roget_dat.txt.gz','r')
-    except:
-        fh=open("roget_dat.txt","r")
+    import gzip
+    fh=gzip.open('roget_dat.txt.gz','r')
 
     G=DiGraph()
 
     for line in fh.readlines():
+        line = line.decode()
         if line.startswith("*"): # skip comments
             continue
         if line.startswith(" "): # this is a continuation line, append
@@ -67,7 +66,7 @@ def roget_graph():
 
         for tail in tails.split():
             if head==tail:
-                print >>sys.stderr,"skipping self loop",head,tail
+                print("skipping self loop",head,tail, file=sys.stderr)
             G.add_edge(head,tail)
 
     return G            
@@ -75,9 +74,9 @@ def roget_graph():
 if __name__ == '__main__':
     from networkx import *
     G=roget_graph()
-    print "Loaded roget_dat.txt containing 1022 categories."
-    print "digraph has %d nodes with %d edges"\
-          %(number_of_nodes(G),number_of_edges(G))
+    print("Loaded roget_dat.txt containing 1022 categories.")
+    print("digraph has %d nodes with %d edges"\
+          %(number_of_nodes(G),number_of_edges(G)))
     UG=G.to_undirected()
-    print number_connected_components(UG),"connected components"
+    print(number_connected_components(UG),"connected components")
 
diff --git a/examples/graph/unix_email.py b/examples/graph/unix_email.py
index b1f87230..f7d42979 100755
--- a/examples/graph/unix_email.py
+++ b/examples/graph/unix_email.py
@@ -24,7 +24,7 @@ __author__ = """Aric Hagberg (hagberg@lanl.gov)"""
 #    BSD license.
 
 import email
-from email.Utils import getaddresses,parseaddr
+from email.utils import getaddresses,parseaddr
 import mailbox
 import sys
 
@@ -48,12 +48,11 @@ if __name__ == '__main__':
         pass
 
     if len(sys.argv)==1:
-        file="unix_email.mbox"
+        filePath = "unix_email.mbox"
     else:
-        file=sys.argv[1]
-    fp=open(file,"r")
+        filePath = sys.argv[1]
 
-    mbox = mailbox.UnixMailbox(fp, msgfactory) # parse unix mailbox
+    mbox = mailbox.mbox(filePath, msgfactory) # parse unix mailbox
 
     G=nx.MultiDiGraph() # create empty graph
 
@@ -73,7 +72,7 @@ if __name__ == '__main__':
 
     # print edges with message subject
     for (u,v,d) in G.edges_iter(data=True):
-        print "From: %s To: %s Subject: %s"%(u,v,d['message']["Subject"])
+        print("From: %s To: %s Subject: %s"%(u,v,d['message']["Subject"]))
     
 
     try: # draw
diff --git a/examples/graph/words.py b/examples/graph/words.py
index 2f1660d2..7411611b 100644
--- a/examples/graph/words.py
+++ b/examples/graph/words.py
@@ -58,49 +58,47 @@ def words_graph():
     """ Return the words example graph from the Stanford GraphBase"""
 
     import sys
-    # open file words_dat.txt.gz (or words_dat.txt)
-    try:
-        import gzip
-        fh=gzip.open('words_dat.txt.gz','r')
-    except:
-        fh=open("words_dat.txt","r")
+    # open file words_dat.txt.gz
+    import gzip
+    fh=gzip.open('words_dat.txt.gz','r')
 
     G = Graph(name="words")
     sys.stderr.write("Loading words_dat.txt: ")
     for line in fh.readlines():
+        line = line.decode()
         if line.startswith("*"):
             continue
         w=line[0:5]
         G.add_node(w)
     nwords=number_of_nodes(G)
     words=G.nodes()
-    for k in xrange(0,nwords):
+    for k in range(0,nwords):
         if (k%100==0): 
             sys.stderr.softspace=0
             sys.stderr.write(".")
-        for l in xrange(k+1,nwords):
+        for l in range(k+1,nwords):
             if _wdist(words[k],words[l]) == 1:
                 G.add_edge(words[k],words[l])
+    print()
     return G
 
 
 if __name__ == '__main__':
     from networkx import *
     G=words_graph()
-    print "Loaded words_dat.txt containing 5757 five-letter English words."
-    print "Two words are connected if they differ in one letter."
-    print "graph has %d nodes with %d edges"\
-          %(number_of_nodes(G),number_of_edges(G))
+    print("Loaded words_dat.txt containing 5757 five-letter English words.")
+    print("Two words are connected if they differ in one letter.")
+    print("graph has %d nodes with %d edges"
+          %(number_of_nodes(G),number_of_edges(G)))
 
     sp=shortest_path(G, 'chaos', 'order')
-    print "shortest path between 'chaos' and 'order' is:\n", sp
+    print("shortest path between 'chaos' and 'order' is:\n%s" % sp)
 
     sp=shortest_path(G, 'nodes', 'graph')
-    print "shortest path between 'nodes' and 'graph' is:\n", sp
+    print("shortest path between 'nodes' and 'graph' is:\n%s" % sp)
 
     sp=shortest_path(G, 'pound', 'marks')
-    print "shortest path between 'pound' and 'marks' is:\n", sp
+    print("shortest path between 'pound' and 'marks' is:\n%s" % sp)
 
-    print number_connected_components(G),"connected components"
+    print("%d connected components" % number_connected_components(G))
 
-