Initial data commit

Task/Unbias-a-random-generator/Python/unbias-a-random-generator.py

@@ -0,0 +1,28 @@
+from __future__ import print_function
+import random
+
+def randN(N):
+    " 1,0 random generator factory with 1 appearing 1/N'th of the time"
+    return lambda: random.randrange(N) == 0
+
+def unbiased(biased):
+    'uses a biased() generator of 1 or 0, to create an unbiased one'
+    this, that = biased(), biased()
+    while this == that: # Loop until 10 or 01
+        this, that = biased(), biased()
+    return this         # return the first
+
+if __name__ == '__main__':
+    from collections import namedtuple
+
+    Stats = namedtuple('Stats', 'count1 count0 percent')
+
+    for N in range(3, 7):
+        biased = randN(N)
+        v = [biased() for x in range(1000000)]
+        v1, v0 = v.count(1), v.count(0)
+        print ( "Biased(%i)  = %r" % (N, Stats(v1, v0, 100. * v1/(v1 + v0))) )
+
+        v = [unbiased(biased) for x in range(1000000)]
+        v1, v0 = v.count(1), v.count(0)
+        print ( "  Unbiased = %r" % (Stats(v1, v0, 100. * v1/(v1 + v0)), ) )