Add type hints to handshake, inverse, mathematicalconstants

axelrod/strategies/handshake.py

@@ -1,6 +1,8 @@
-from axelrod.actions import Actions
+from axelrod.actions import Actions, Action
 from axelrod.player import Player
 
+from typing import List
+
 C, D = Actions.C, Actions.D
 
 
@@ -24,13 +26,13 @@ class Handshake(Player):
         'manipulates_state': False
     }
 
-    def __init__(self, initial_plays=None):
+    def __init__(self, initial_plays: List[Action]=None) -> None:
         super().__init__()
         if not initial_plays:
             initial_plays = [C, D]
         self.initial_plays = initial_plays
 
-    def strategy(self, opponent):
+    def strategy(self, opponent: Player) -> Action:
         # Begin by playing the sequence C, D
         index = len(self.history)
         if index < len(self.initial_plays):

axelrod/strategies/inverse.py

@@ -1,4 +1,4 @@
-from axelrod.actions import Actions
+from axelrod.actions import Actions, Action
 from axelrod.player import Player
 from axelrod.random_ import random_choice
 
@@ -21,7 +21,7 @@ class Inverse(Player):
     }
 
     @staticmethod
-    def strategy(opponent):
+    def strategy(opponent: Player) -> Action:
         """Looks at opponent history to see if they have defected.
 
         If so, player defection is inversely proportional to when this occurred.

axelrod/strategies/mathematicalconstants.py

@@ -1,7 +1,9 @@
 import math
-from axelrod.actions import Actions
+
+from axelrod.actions import Actions, Action
 from axelrod.player import Player
 
+C, D = Actions.C, Actions.D
 
 class CotoDeRatio(Player):
     """The player will always aim to bring the ratio of co-operations to
@@ -20,16 +22,16 @@ class CotoDeRatio(Player):
     def strategy(self, opponent):
         # Initially cooperate
         if len(opponent.history) == 0:
-            return Actions.C
+            return C
         # Avoid initial division by zero
         if not opponent.defections:
-            return Actions.D
+            return D
         # Otherwise compare ratio to golden mean
         cooperations = opponent.cooperations + self.cooperations
         defections = opponent.defections + self.defections
         if cooperations / defections > self.ratio:
-            return Actions.D
-        return Actions.C
+            return D
+        return C
 
 
 class Golden(CotoDeRatio):

type_tests.sh

@@ -23,3 +23,6 @@ mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/forgiver.
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/gradualkiller.py
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/grudger.py
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/grumpy.py
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/handshake.py
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/inverse.py
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/mathematicalconstants.py