September Morn Update

Task/Perfect-numbers/Python/perfect-numbers-2.py

@@ -1 +1,6 @@
-perf = lambda n: n == sum(i for i in xrange(1, n) if n % i == 0)
+def perf(n):
+    return n == sum(i for i in range(1, n) if n % i == 0)
+
+print (
+    list(filter(perf, range(1, 10001)))
+)

Task/Perfect-numbers/Python/perfect-numbers-3.py

@@ -0,0 +1,35 @@
+'''Perfect numbers'''
+
+from math import sqrt
+
+
+# perfect :: Int - > Bool
+def perfect(n):
+    '''Is n the sum of its proper divisors other than 1 ?'''
+
+    root = sqrt(n)
+    lows = [x for x in enumFromTo(2)(int(root)) if 0 == (n % x)]
+    return 1 < n and (
+        n == 1 + sum(lows + [n / x for x in lows if root != x])
+    )
+
+
+# main :: IO ()
+def main():
+    '''Test'''
+
+    print([
+        x for x in enumFromTo(1)(10000) if perfect(x)
+    ])
+
+
+# GENERIC -------------------------------------------------
+
+# enumFromTo :: (Int, Int) -> [Int]
+def enumFromTo(m):
+    '''Integer enumeration from m to n.'''
+    return lambda n: list(range(m, 1 + n))
+
+
+if __name__ == '__main__':
+    main()