Makes Graph.nodes() return iterator instead of list

Previously `Graph.nodes()` returned a list of nodes and
`Graph.nodes_iter()` returned an iterator over nodes. With this commit,
the former function now returns an iterator and the latter no longer
exists.

1 files changed, 9 insertions, 13 deletions

diff --git a/networkx/relabel.py b/networkx/relabel.py
index d00ba3a7..c188cc1c 100644
--- a/networkx/relabel.py
+++ b/networkx/relabel.py
@@ -41,20 +41,17 @@ def relabel_nodes(G, mapping, copy=True):
 
     Partial in-place mapping:
 
-    >>> G=nx.path_graph(3)  # nodes 0-1-2
-    >>> mapping={0:'a',1:'b'} # 0->'a' and 1->'b'
-    >>> G=nx.relabel_nodes(G,mapping, copy=False)
-
-    print(G.nodes())
-    [2, 'b', 'a']
+    >>> G = nx.path_graph(3)  # nodes 0-1-2
+    >>> mapping = {0: 'a', 1: 'b'} # 0->'a' and 1->'b'
+    >>> G = nx.relabel_nodes(G, mapping, copy=False)
+    >>> sorted(G, key=str)
+    [2, 'a', 'b']
 
     Mapping as function:
 
-    >>> G=nx.path_graph(3)
-    >>> def mapping(x):
-    ...    return x**2
-    >>> H=nx.relabel_nodes(G,mapping)
-    >>> print(H.nodes())
+    >>> G = nx.path_graph(3)
+    >>> H = nx.relabel_nodes(G, lambda x: x ** 2)
+    >>> list(H)
     [0, 1, 4]
 
     Notes
@@ -184,8 +181,7 @@ def convert_node_labels_to_integers(G, first_label=0, ordering="default",
     if ordering == "default":
         mapping = dict(zip(G.nodes(), range(first_label, N)))
     elif ordering == "sorted":
-        nlist = G.nodes()
-        nlist.sort()
+        nlist = sorted(G.nodes())
         mapping = dict(zip(nlist, range(first_label, N)))
     elif ordering == "increasing degree":
         dv_pairs = [(d,n) for (n,d) in G.degree_iter()]