btree_bucket_size.py

from ZODB import DB
from BTrees.IIBTree import IIBTree
import transaction

def populate_tree():
    db = DB('fuckme.fs')
    connection = db.open()
    root = connection.root()
    tree = root['tree'] = IIBTree()
    for i in xrange(1000000):
        tree[i] = 1
    transaction.commit()
    connection.cacheMinimize()
    return tree

def main():
    tree = populate_tree()
    print('done')

if __name__ == '__main__':
    main()