Now do a proper FutureWarning on setting a player to have the same label as another.

Author: tturocy

src/pygambit/action.pxi

@@ -77,9 +77,9 @@ class Action:
 
     @label.setter
     def label(self, value: str) -> None:
-        if (value == "" or value.encode("ascii") in
-                (action.deref().GetLabel()
-                 for action in self.action.deref().GetInfoset().deref().GetActions())):
+        if value == self.label:
+            return
+        if value == "" or value in (act.label for act in self.infoset.actions):
             warnings.warn("In a future version, actions must have unique labels "
                           "within their information set",
                           FutureWarning)

src/pygambit/player.pxi

@@ -192,9 +192,11 @@ class Player:
 
     @label.setter
     def label(self, value: str) -> None:
-        # check to see if the player's name has been used elsewhere
-        if value in [i.label for i in self.game.players]:
-            warnings.warn("Another player with an identical label exists")
+        if value == self.label:
+            return
+        if value == "" or value in (player.label for player in self.game.players):
+            warnings.warn("In a future version, players must have unique labels",
+                          FutureWarning)
         self.player.deref().SetLabel(value.encode("ascii"))
 
     @property

tests/test_players.py

@@ -61,6 +61,18 @@ def test_player_label_invalid():
         _ = game.players["Not a player"]
 
 
+def test_set_empty_player_futurewarning():
+    game = games.create_stripped_down_poker_efg()
+    with pytest.warns(FutureWarning):
+        game.players[0].label = ""
+
+
+def test_set_duplicate_player_futurewarning():
+    game = games.create_stripped_down_poker_efg()
+    with pytest.warns(FutureWarning):
+        game.players[0].label = game.players[1].label
+
+
 def test_strategic_game_add_player():
     game = gbt.Game.new_table([2, 2])
     game.add_player()