Fix strategy and adjust tests.

Author: drvinceknight

axelrod/strategies/titfortat.py

@@ -642,10 +642,10 @@ def strategy(self, opponent: Player) -> Action:
 class Alexei(Player):
     """
     Plays similar to Tit-for-Tat, but always defect on last turn.
-    
+
     Names:
 
-    - Alexei's Strategy: [LessWrong2011]_    
+    - Alexei's Strategy: [LessWrong2011]_
     """
 
     name = 'Alexei'
@@ -672,10 +672,10 @@ class EugineNier(Player):
     Plays similar to Tit-for-Tat, but with two conditions:
     1) Always Defect on Last Move
     2) If other player defects five times, switch to all defects.
-    
+
     Names:
 
-    - EugineNier Strategy: [LessWrong2011]_    
+    - EugineNier Strategy: [LessWrong2011]_
     """
 
     name = 'EugineNier'
@@ -689,11 +689,18 @@ class EugineNier(Player):
         'manipulates_state': False
     }
 
+    def __init__(self):
+        super().__init__()
+        self.is_defector = False
+
     def strategy(self, opponent: Player) -> Action:
         if not self.history:
             return C
-        if opponent.history[-5:] == [D, D, D, D, D]:
-            return D
-        if opponent.history[-1] == D:
+        if self.is_defector or opponent.history[-5:] == [D] * 5:
+            self.is_defector = True
             return D
-        return C
+        return opponent.history[-1]
+
+    def reset(self):
+        super().reset()
+        self.is_defector = False

axelrod/tests/strategies/test_titfortat.py

@@ -593,7 +593,7 @@ def test_strategy(self):
         actions = [(C, C), (C, D), (D, C), (C, D), (D, C), (C, D)]
         self.versus_test(axelrod.Alternator(), expected_actions=actions,
                          match_attributes={"length": -1})
-        
+
         actions = [(C, C), (C, D), (D, C), (C, D), (D, C), (D, D)]
         self.versus_test(axelrod.Alternator(), expected_actions=actions)
 
@@ -621,23 +621,27 @@ def test_strategy(self):
         self.first_play_test(C)
         self.second_play_test(rCC=C, rCD=D, rDC=C, rDD=D)
 
-        actions = [(C, C), (C, C), (C, C), (C, C), (D, C)]
+        actions = [(C, C), (C, C), (C, C), (D, C)]
         self.versus_test(axelrod.Cooperator(), expected_actions=actions)
 
-        actions = [(C, D), (D, D), (D, D), (D, D), (D, D)]
-        self.versus_test(axelrod.Defector(), expected_actions=actions)
+        actions = [(C, C), (C, C), (C, C), (C, C)]
+        self.versus_test(axelrod.Cooperator(), expected_actions=actions,
+                         match_attributes={"length": -1})
+
+
+        # Plays TfT and defects in last round
+        actions = [(C, C), (C, D), (D, C), (C, D), (D, C), (D, D)]
+        self.versus_test(axelrod.Alternator(), expected_actions=actions)
 
         actions = [(C, C), (C, D), (D, C), (C, D), (D, C), (C, D)]
         self.versus_test(axelrod.Alternator(), expected_actions=actions,
                          match_attributes={"length": -1})
-        
+
         actions = [(C, C), (C, D), (D, C), (C, D), (D, C), (D, D)]
         self.versus_test(axelrod.Alternator(), expected_actions=actions)
 
-        opponent = axelrod.MockPlayer(actions=[C, C, D, D, C, D])
-        actions = [(C, C), (C, C), (C, D), (D, D), (D, C), (D, D)]
-        self.versus_test(opponent, expected_actions=actions)
-        
-        opponent = axelrod.MockPlayer(actions=[C, D, D, D, D, D])
-        actions = [(C, C), (D, D), (D, D), (D, D), (D, D), (D, D)]
+        # Becomes defector after 5 defections
+        opponent = axelrod.MockPlayer(actions=[C, D, D, D, D, D, C, C])
+        actions = [(C, C), (C, D), (D, D), (D, D),
+                   (D, D), (D, D), (D, C), (D, C)]
         self.versus_test(opponent, expected_actions=actions)