Converting docstrings C and D to 'C' and 'D'

Also including an example with m=3 and n=2.

Author: drvinceknight

axelrod/strategies/lookerup.py

@@ -18,38 +18,53 @@ class LookerUp(Player):
     - my last action was a C the opponents
     - last action was a D
     then the corresponding key would be
-        (C, C, D)
+        ('C', 'C', 'D')
     and the value would contain the action to play on this turn.
 
     Some well-known strategies can be expressed as special cases; for example
     Cooperator is given by the dict:
         {('', '', '') : C}
     where m and n are both zero. Tit-For-Tat is given by:
+
     {
-        ('', C, D) : D,
-        ('', D, D) : D,
-        ('', C, C) : C,
-        ('', D, C) : C,
+        ('', 'C', 'D') : D,
+        ('', 'D', 'D') : D,
+        ('', 'C', 'C') : C,
+        ('', 'D', 'C') : C,
     }
+
     where m=1 and n=0.
 
     Lookup tables where the action depends on the opponent's first actions (as
     opposed to most recent actions) will have a non-empty first string in the
     tuple. For example, this fragment of a dict:
+
     {
         ...
-        (C, C, C) : C.
-        (D, C, C) : D,
+        ('C', 'C', 'C') : C.
+        ('D', 'C', 'C') : D,
         ...
     }
+
     states that if self and opponent both cooperated on the previous turn, we
     should cooperate this turn unless the opponent started by defecting, in
     which case we should defect.
+
+    To denote lookup tables where the action depends on sequences of actions
+    (so m or n are greater than 1), simply concatenate the strings together.
+    Below is an incomplete example where m=3 and n=2.
+
+    {
+        ...
+        ('CC', 'CDD', 'CCC') : C.
+        ('CD', 'CCD', 'CCC') : D,
+        ...
+    }
     """
 
     name = 'LookerUp'
     classifier = {
-        'memory_depth': float('inf'), 
+        'memory_depth': float('inf'),
         'stochastic': False,
         'inspects_source': False,
         'manipulates_source': False,
@@ -63,11 +78,11 @@ def __init__(self, lookup_table=None):
         Player.__init__(self)
 
         if not lookup_table:
-            lookup_table = { 
-            ('', C, D) : D,
-            ('', D, D) : D,
-            ('', C, C) : C,
-            ('', D, C) : C,
+            lookup_table = {
+            ('', 'C', 'D') : D,
+            ('', 'D', 'D') : D,
+            ('', 'C', 'C') : C,
+            ('', 'D', 'C') : C,
         }
 
         self.lookup_table = lookup_table