Clean up of utility functions

Improve legibility of functions in bot_utils.  Most of this is by using
list comprehensions instead of maps ands filters, but there were also
some changes to local variable names and definitions.  No feature
changes are intended, and test/regression.py shows none.  Heuristics
player was also added to the test suite, although it doesn't appear to
be complete yet.

bot_utils.py

@@ -31,13 +31,13 @@ def get_duplicate_cards(cards):
 def get_visible_cards(cards1, cards2):
     """Return a list of the intersection of cards1 and cards2; call only on
     visible cards!"""
-    names2 = map(lambda x: x['name'], cards2)
-    return list(filter(lambda x: x['name'] in names2, cards1))
+    names2 = [card['name'] for card in cards2]
+    return [card for card in cards1 if card['name'] in names2]
 
 def get_nonvisible_cards(cards1, names2):
     """Return a list of cards that are in cards1 but not names2; call only on
     visible cards!"""
-    return list(filter(lambda x: x['name'] not in names2, cards1))
+    return [card for card in cards1 if card['name'] not in names2]
 
 def possible_hints(card):
     name = card['name']
@@ -61,17 +61,19 @@ def deduce_plays(cards, progress, suits):
             if info in suits:
                 if suit == '':
                     suit = info
-                    if '?' in suits:
-                        suit += '?' # With one hint, can't rule out rainbow.
+                    if RAINBOW_SUIT in suits:
+                        # With one hint, can't rule out rainbow.
+                        suit += RAINBOW_SUIT
                 elif suit not in info:
-                    suit = '?' # Rainbow card matches more than one suit.
-            elif info in '123456789': # Maybe we'll add variants later.
+                    # Rainbow card matches more than one suit.
+                    suit = RAINBOW_SUIT
+            elif info in SUIT_CONTENTS:
                 value = info
 
         if len(suit) == 2: # Try to deduce that card is not rainbow.
             for info in card['indirect']:
                 if info in suits:
-                    suit = suit.replace('?', '')
+                    suit = suit.replace(RAINBOW_SUIT, '')
                     break # Already found the info we needed.
 
         if len(suit) == 1 and value != '' and progress[suit] == int(value) - 1:
@@ -85,20 +87,19 @@ def playable_cards(progress):
                 if value < 5]
 
 def cards_possibly_in_set(card, card_name_array):
-    """Get all the cards that could possibly be in the set given the info that
-       we know from hints only."""
-    ret = [name for name in card_name_array
+    """Given a list of card names, return only those which are consistent
+       with the hinted information about card (non-visible)."""
+    return [name for name in card_name_array
             if (all(matches(name, hint) for hint in card['direct']) and not
                 any(matches(name, hint) for hint in card['indirect']))]
-    return ret
 
 def possibly_playable(card, progress):
     """Check if it is possible with current knowledge that card is playable"""
     playables = playable_cards(progress)
     return cards_possibly_in_set(card, playables)
 
 def matches(name, hint):
-    """"Name is the card including number+suit, hint is single char"""
+    """Name is the card including number+suit, hint is single char"""
     return (hint in name or (hint in VANILLA_SUITS and RAINBOW_SUIT in name))
 
 def other_players(me, r):
@@ -108,8 +109,9 @@ def other_players(me, r):
 def count_unique_future_plays(cards, progress):
     """Returns the number of plays or future plays,
     counting duplicate cards only once; call only on visible cards!"""
-    unique_names = list(set(map(lambda x: x['name'], cards)))
-    return len(list(filter(lambda x: int(x[0]) > progress[x[1]], unique_names)))
+    remaining_plays = \
+        set([card['name'] for card in cards if is_playable(card, progress)])
+    return len(remaining_plays)
 
 def get_all_visible_cards(player, r):
     """Returns list of visible cards for player"""

test/regression.py

@@ -20,7 +20,8 @@
               'cheater',
               'brainbow',
               'newest',
-              'hat'}
+              'hat',
+              'heuristic'}
 
 parser = argparse.ArgumentParser(description='record, test, or cleanup')
 parser.add_argument('-r', '--record', help="record current output",