Initial data commit

Task/Vampire-number/Python/vampire-number-2.py

@@ -0,0 +1,23 @@
+from math import sqrt
+from itertools import imap, ifilter, islice, count
+
+def factor_pairs(n):
+    return ((x, n // x) for x in xrange(2, int(sqrt(n))) if n % x == 0)
+
+def fangs(n):
+    dlen = lambda x: len(str(x))
+    half = dlen(n) // 2
+    digits = lambda (x, y): sorted(str(x) + str(y))
+    halvesQ = lambda xs: all(y == half for y in imap(dlen, xs))
+    dn = sorted(str(n))
+    return [p for p in factor_pairs(n) if halvesQ(p) and dn==digits(p)]
+
+def vampiricQ(n):
+    fn = fangs(n)
+    return (n, fn) if fn else None
+
+for v in islice(ifilter(None, imap(vampiricQ, count())), 0, 25):
+    print v
+
+for n in [16758243290880, 24959017348650, 14593825548650]:
+    print vampiricQ(n) or str(n) + " is not vampiric."