Another update from ingydotnet^djgoku

Task/Evolutionary-algorithm/Python/evolutionary-algorithm-1.py

@@ -1,13 +1,14 @@
-from string import ascii_uppercase
+from string import letters
 from random import choice, random
 
 target  = list("METHINKS IT IS LIKE A WEASEL")
-charset = ascii_uppercase + ' '
+charset = letters + ' '
 parent  = [choice(charset) for _ in range(len(target))]
 minmutaterate  = .09
 C = range(100)
 
 perfectfitness = float(len(target))
+
 def fitness(trial):
     'Sum of matching chars by position'
     return sum(t==h for t,h in zip(trial, target))
@@ -24,12 +25,23 @@ def que():
     print ("#%-4i, fitness: %4.1f%%, '%s'" %
            (iterations, fitness(parent)*100./perfectfitness, ''.join(parent)))
 
+def mate(a, b):
+    place = 0
+    if choice(xrange(10)) < 7:
+        place = choice(xrange(len(target)))
+    else:
+        return a, b
+
+    return a, b, a[:place] + b[place:], b[:place] + a[place:]
+
 iterations = 0
+center = len(C)/2
 while parent != target:
-    rate =  mutaterate()
+    rate = mutaterate()
     iterations += 1
     if iterations % 100 == 0: que()
     copies = [ mutate(parent, rate) for _ in C ]  + [parent]
-    parent = max(copies, key=fitness)
-print ()
+    parent1 = max(copies[:center], key=fitness)
+    parent2 = max(copies[center:], key=fitness)
+    parent = max(mate(parent1, parent2), key=fitness)
 que()