Fix: comportement dans le cas où il n'y a pas encore de séquence

tasks.py

@@ -75,8 +75,14 @@ def sequence_prompt(
     )
 
     sequences = get_sequences(sequence["tribe"])
-    print("Séquences trouvées:\n\t" + "\n\t".join(sorted([s.name for s in sequences])))
-    sequence["num"] = max([int(seq.name[0:2]) for seq in sequences]) + 1
+    if sequences:
+        print("Séquences trouvées:\n\t" +
+              "\n\t".join(sorted([s.name for s in sequences])))
+        sequence["num"] = max([int(seq.name[0:2]) for seq in sequences]) + 1
+    else:
+        print("Pas de séquence trouvée")
+        sequence["num"] = 1
+
     sequence["title"] = prompt(
         f"Nom de la séquence (n°{sequence['num']}): ", default=title
     )
@@ -147,4 +153,3 @@ def sequence(c):
 
     sequence["title_under"] = "#" * len(sequence["title"])
     import_skel(dest, sequence, "sequence")
-