gistfile1.pyw

#!/usr/bin/env python

# http://stackoverflow.com/questions/3139869/heapq-nlargest-index-of-returned-result-in-original-sequence/3139918#3139918

import heapq
from timeit import Timer

seq = [100, 2, 400, 500, 400] + range(9995)
# seq = ("hello", 2, "world", 500, 400)

def a(seq, n=2):
    """
    returns [(3, 500), (2, 400)]
    """
    return heapq.nlargest(n, enumerate(seq), key=lambda x: x[1])

def b(seq, n=2):
    """
    returns [3, 2]
    """
    return map(seq.index, heapq.nlargest(n, seq))

def c(seq, n=2):
    """
    returns [(500, 3), (400, 2)]
    """
    map(lambda n: (n, seq.index(n)), heapq.nlargest(n, seq))


if __name__ == '__main__':
    
    loops, n = 1000, 100
    
    _a = Timer("a(seq, n=%s)" % n, "from __main__ import a, seq")
    _b = Timer("b(seq, n=%s)" % n, "from __main__ import b, seq")
    _c = Timer("c(seq, n=%s)" % n, "from __main__ import c, seq") 

    print _a.timeit(number=loops)
    print _b.timeit(number=loops)
    print _c.timeit(number=loops)