diff --git a/create_graph_dumb.py b/create_graph_dumb.py
index 0143e2398fcad1e3bac65ceb24360f484df02767..2d78d967286c935520b1a9d51c713c2e695c88b9 100644
--- a/create_graph_dumb.py
+++ b/create_graph_dumb.py
@@ -34,7 +34,7 @@ def ntf_parse(args):
 
         node_a = mapping.setdefault(node_a, len(mapping))
         node_b = mapping.setdefault(node_b, len(mapping))
-        
+
         c_ab = int(tab[2])
         nodes.setdefault(node_a, list()).append((node_b, c_ab))
 
@@ -45,10 +45,11 @@ def to_header_file(nodes, nb_links, output):
     # Check that the extension is correct.
     _, file_extension = os.path.splitext(output)
     if file_extension != ".h":
-        warnings.warn(f'The extension of the output file is not ".h": {output}')
+        warnings.warn(
+            f'The extension of the output file is not ".h": {output}')
 
     s = ""
-    
+
     # Create the array containing the links.
     for node_id, neighs in nodes.items():
         for (neigh_id, cost) in neighs:
@@ -84,7 +85,8 @@ if __name__ == "__main__":
                         help="Number of nodes. Unused if '--ntf'", default=5)
     parser.add_argument("-l", "--links", type=int,
                         help="Number of links. Unused if '--ntf'", default=10)
-    parser.add_argument("--c-header", action="store_true", help="Writes the graph as a C header file (.h) instead of a binary file")
+    parser.add_argument("--c-header", action="store_true",
+                        help="Writes the graph as a C header file (.h) instead of a binary file")
     args = parser.parse_args()
 
     if args.ntf: