Merge pull request #1152 from Nikoleta-v3/fix-tideman-chieruzzi

fixes implementation error in TidemanAndChieruzzi

Author: drvinceknight

axelrod/strategies/axelrod_first.py

@@ -673,7 +673,7 @@ def strategy(self, opponent: Player) -> Action:
                 std_deviation = (N ** (1 / 2)) / 2
                 lower = N / 2 - 3 * std_deviation
                 upper = N / 2 + 3 * std_deviation
-                if self.defections <= lower or self.defections >= upper:
+                if opponent.defections <= lower or opponent.defections >= upper:
                     # Opponent deserves a fresh start
                     self.last_fresh_start = current_round
                     self._fresh_start()

axelrod/tests/strategies/test_axelrod_first.py

@@ -473,33 +473,34 @@ def test_strategy(self):
                                 'retaliation_length': 4,
                                 'retaliation_remaining': 3})
 
-        # A fresh starts occurs on round 14.
         opponent = axelrod.Cycler('DDCDD')
         actions = [(C, D), (D, D), (D, C), (D, D), (D, D),
                    (D, D), (D, D), (D, C), (D, D), (D, D),
-                   (D, D), (D, D), (D, C), (C, D), (C, D),
-                   (D, D), (D, D), (D, C), (C, D), (D, D),
+                   (D, D), (D, D), (D, C), (D, D), (D, D),
                    (D, D), (D, D), (D, C), (D, D), (D, D)]
-
         self.versus_test(opponent, expected_actions=actions,
-                         attrs={'current_score': 40, 'opponent_score': 35,
-                                'last_fresh_start': 14,
-                                'retaliation_length': 4,
-                                'retaliation_remaining': 1})
+                         attrs={'current_score': 34, 'opponent_score': 19,
+                                'last_fresh_start': 0,
+                                'retaliation_length': 6,
+                                'retaliation_remaining': 2})
 
         # When the length is given this strategy will not give a fresh start
         opponent = axelrod.Cycler('DDCDD')
-        actions = [(C, D), (D, D), (D, C), (D, D), (D, D),
-                   (D, D), (D, D), (D, C), (D, D), (D, D),
-                   (D, D), (D, D), (D, C), (D, D), (D, D)]
+        actions = [(C, D), (D, D), (D, C), (D, D), (D, D), (D, D), (D, D),
+                   (D, C), (D, D), (D, D), (D, D), (D, D), (D, C), (D, D),
+                   (D, D), (D, D), (D, D), (D, C), (D, D), (D, D), (D, D),
+                   (D, D), (D, C), (D, D), (D, D), (D, D), (D, D), (D, C),
+                   (C, D), (C, D)]
         self.versus_test(opponent, expected_actions=actions,
-                         match_attributes={'length': 15})
+                         match_attributes={'length': 50})
 
         # When the length is not given this strategy will give a fresh start.
         opponent = axelrod.Cycler('DDCDD')
-        actions = [(C, D), (D, D), (D, C), (D, D), (D, D),
-                   (D, D), (D, D), (D, C), (D, D), (D, D),
-                   (D, D), (D, D), (D, C), (C, D), (C, D)]
+        actions = [(C, D), (D, D), (D, C), (D, D), (D, D), (D, D), (D, D),
+                   (D, C), (D, D), (D, D), (D, D), (D, D), (D, C), (D, D),
+                   (D, D), (D, D), (D, D), (D, C), (D, D), (D, D), (D, D),
+                   (D, D), (D, C), (D, D), (D, D), (D, D), (D, D), (D, C),
+                   (C, D), (C, D)]
         self.versus_test(opponent, expected_actions=actions,
                          match_attributes={'length': float('inf')})
 
@@ -522,4 +523,18 @@ def test_strategy(self):
         self.versus_test(opponent, expected_actions=actions,
                          attrs={'fresh_start': False})
 
+        # check the fresh start condition: least 20 rounds since the last ‘fresh start’
+        opponent = axelrod.Cycler('CCCCD') 
+        actions = [(C, C), (C, C), (C, C), (C, C), (C, D), (D, C), (C, C), 
+                   (C, C), (C, C), (C, D), (D, C), (D, C), (C, C), (C, C), 
+                   (C, D), (D, C), (D, C), (D, C), (C, C), (C, D), (D, C), 
+                   (D, C), (D, C), (C, C), (C, D), (D, C), (C, C), (C, C), 
+                   (C, C), (C, D), (D, C), (D, C), (C, C), (C, C), (C, D)]
+        self.versus_test(opponent, expected_actions=actions,
+                         match_attributes={'length': 35},
+                         attrs={'current_score': 108, 'opponent_score': 78,
+                                'last_fresh_start': 24,
+                                'retaliation_length': 2,
+                                'retaliation_remaining': 0})
+