Convert %-format to fstring

1 files changed, 2 insertions, 2 deletions

diff --git a/networkx/relabel.py b/networkx/relabel.py
index d93402ea..ab1779e1 100644
--- a/networkx/relabel.py
+++ b/networkx/relabel.py
@@ -124,7 +124,7 @@ def _relabel_inplace(G, mapping):
         try:
             G.add_node(new, **G.nodes[old])
         except KeyError:
-            raise KeyError("Node %s is not in the graph" % old)
+            raise KeyError(f"Node {old} is not in the graph")
         if multigraph:
             new_edges = [(new, new if old == target else target, key, data)
                          for (_, target, key, data)
@@ -210,7 +210,7 @@ def convert_node_labels_to_integers(G, first_label=0, ordering="default",
         dv_pairs.reverse()
         mapping = dict(zip([n for d, n in dv_pairs], range(first_label, N)))
     else:
-        raise nx.NetworkXError('Unknown node ordering: %s' % ordering)
+        raise nx.NetworkXError(f"Unknown node ordering: {ordering}")
     H = relabel_nodes(G, mapping)
     # create node attribute with the old label
     if label_attribute is not None: