aimacode · norvig · Apr 18, 2016 · Apr 17, 2016
diff --git a/agents.py b/agents.py
@@ -848,7 +848,7 @@ def score(env):
         env.add_thing(agent)
         env.run(steps)
         return agent.performance
-    return mean(list(map(score, envs)))
+    return mean(map(score, envs))
 
 # _________________________________________________________________________
 

diff --git a/csp.py b/csp.py
@@ -510,7 +510,7 @@ def flatten(seqs): return sum(seqs, [])
 _CELL = itertools.count().__next__
 _BGRID = [[[[_CELL() for x in _R3] for y in _R3] for bx in _R3] for by in _R3]
 _BOXES = flatten([list(map(flatten, brow)) for brow in _BGRID])
-_ROWS = flatten([list(map(flatten, list(zip(*brow)))) for brow in _BGRID])
+_ROWS = flatten([list(map(flatten, zip(*brow))) for brow in _BGRID])
 _COLS = list(zip(*_ROWS))
 
 _NEIGHBORS = {v: set() for v in flatten(_ROWS)}
@@ -583,7 +583,7 @@ def abut(lines1, lines2): return list(
             map(' | '.join, list(zip(lines1, lines2))))
         print('\n------+-------+------\n'.join(
             '\n'.join(reduce(
-                abut, list(map(show_box, brow)))) for brow in self.bgrid))
+                abut, map(show_box, brow))) for brow in self.bgrid))
 # ______________________________________________________________________________
 # The Zebra Puzzle
 

diff --git a/learning.py b/learning.py
@@ -101,14 +101,14 @@ def setproblem(self, target, inputs=None, exclude=()):
         to not use in inputs. Attributes can be -n .. n, or an attrname.
         Also computes the list of possible values, if that wasn't done yet."""
         self.target = self.attrnum(target)
-        exclude = list(map(self.attrnum, exclude))
+        exclude = map(self.attrnum, exclude)
         if inputs:
             self.inputs = removeall(self.target, inputs)
         else:
             self.inputs = [a for a in self.attrs
                            if a != self.target and a not in exclude]
         if not self.values:
-            self.values = list(map(unique, list(zip(*self.examples))))
+            self.values = list(map(unique, zip(*self.examples)))
         self.check_me()
 
     def check_me(self):

diff --git a/logic.py b/logic.py
@@ -903,7 +903,7 @@ def fetch_rules_for_goal(self, goal):
 
 
 test_kb = FolKB(
-    list(map(expr, ['Farmer(Mac)',
+    map(expr, ['Farmer(Mac)',
                     'Rabbit(Pete)',
                     'Mother(MrsMac, Mac)',
                     'Mother(MrsRabbit, Pete)',
@@ -916,10 +916,9 @@ def fetch_rules_for_goal(self, goal):
                     # '(Human(h) & Mother(m, h)) ==> Human(m)'
                     '(Mother(m, h) & Human(h)) ==> Human(m)'
                     ]))
-)
 
 crime_kb = FolKB(
-    list(map(expr,
+    map(expr,
              ['(American(x) & Weapon(y) & Sells(x, y, z) & Hostile(z)) ==> Criminal(x)',  # noqa
               'Owns(Nono, M1)',
               'Missile(M1)',
@@ -929,7 +928,6 @@ def fetch_rules_for_goal(self, goal):
               'American(West)',
               'Enemy(Nono, America)'
               ]))
-)
 
 
 def fol_bc_ask(KB, query):

diff --git a/search.py b/search.py
@@ -584,7 +584,7 @@ def genetic_algorithm(population, fitness_fn, ngen=1000, pmut=0.1):
     for i in range(ngen):
         new_population = []
         for i in len(population):
-            fitnesses = list(map(fitness_fn, population))
+            fitnesses = map(fitness_fn, population)
             p1, p2 = weighted_sample_with_replacement(population, fitnesses, 2)
             child = p1.mate(p2)
             if random.uniform(0, 1) < pmut:

diff --git a/utils.py b/utils.py
@@ -86,7 +86,7 @@ def histogram(values, mode=0, bin_function=None):
     Sorted by increasing value, or if mode=1, by decreasing count.
     If bin_function is given, map it over values first."""
     if bin_function:
-        values = list(map(bin_function, values))
+        values = map(bin_function, values)
 
     bins = {}
     for val in values:
@@ -299,8 +299,8 @@ def print_table(table, header=None, sep='   ', numfmt='%g'):
              for row in table]
 
     sizes = list(
-            map(lambda seq: max(list(map(len, seq))),
-                list(zip(*[list(map(str, row)) for row in table]))))
+            map(lambda seq: max(map(len, seq)),
+                list(zip(*[map(str, row) for row in table]))))
 
     for row in table:
         print(sep.join(getattr(