memory leak when retrieving pickled objects from file about rtree HOT 2 CLOSED

import rtree
import random
import time

def createDefaultIndex():
    idx = rtree.index.Rtree(u"defaultIndex")

    # make boxes....
    boxes = []
    for boxIndex in range(0,100):
        xmin = random.random()
        ymin = random.random()
        xmax = xmin + random.random()
        ymax = ymin + random.random()
        boxes.append((xmin,ymin,xmax,ymax))

    for boxIndex, box in enumerate(boxes):
        pickledObject = "makethisbig " * 100000
        idx.insert(boxIndex, box, obj=pickledObject)

    del idx

def readIndexDefault():
    indexPath = u"defaultIndex"
    #idx = rtree.index.Rtree(indexPath)
    idx = rtree.index.Index(indexPath)
    boundingCoords = [0,0,60,60]
    print "Consuming Index"
    startTime = time.time()
    #hits = list(idx.intersection(boundingCoords, objects=True)) # memory leak 
    #hits = list(idx.intersection(boundingCoords, objects="raw")) # no memory leak
    hits = list(idx.intersection(boundingCoords, objects=False)) # no memory leak
    #hits = list(idx.intersection(boundingCoords))
    endTime = time.time()
    print "Consuming time: ", endTime - startTime
    print "Hits: ", len(hits)
    time.sleep(10)

    print "Done Consuming - erasing memory"
    idx = None
    hits=None
    for counter in range(0,10):
        time.sleep(1)

# what we have learned: 
# if objects == true, we have memory leak. hits, idx each have
# the size of the dat file and those are released. however, there is
# a 3rd memory allocation for the size of the dat file, mysterious, that
# is not released.
# if object != true, then there is no memory leak.
# if object == "raw" then no memory leak

if name == "main":
    createDefaultIndex()
    readIndexDefault()