python – Pymongo BSON二进制保存和检索？

我可以正确创建和存储*

但我无法以可用的格式检索数据.

>>> import random,array,pymongo
>>> from bson.binary import Binary as BsonBinary
>>> con = pymongo.Connection('localhost',27017)
>>> mm = con['testDatabase']
>>> vals = [random.random() *100 for x in range(1,5)]
>>> vals
[2.9962593,64.5582810776,32.3781311717,82.0606953423]
>>> varray = array.array('f',vals)
>>> varray
array('f',[2.9962593,82.0606953423])
>>> vstring = varray.tostring()
>>> vstring
'xb7xc2?@xd7x1dx81B5x83x01Bx13x1fxa4B'
>>> vbson = BsonBinary(vstring,5)
>>> vbson
Binary('xb7xc2?@xd7x1dx81B5x83x01Bx13x1fxa4B',5)
>>> doc1 = { 'something': 1,'else' : vbson}
>>> doc1
{'something': 1,'else': Binary('xb7xc2?@xd7x1dx81B5x83x01Bx13x1fxa4B',5)}
>>> mm.test1.insert(doc1)
ObjectID('530f7af1d809d80d3db1f635')
>>> gotdoc = mm.test1.find_one()
>>> gotdoc
{u'_id': ObjectId('530f7af1d809d80d3db1f635'),u'something': 3,u'else': Binary('xb7xc2?@xd7x1dx81B5x83x01Bx13x1fxa4B',5)}
>>> gotfield = gotdoc['else']
>>> gotfield
Binary('xb7xc2?@xd7x1dx81B5x83x01Bx13x1fxa4B',5)
>>> from bson import BSON
>>> BSON.decode(gotfield)
Traceback (most recent call last):
  File "<stdin>",line 1,in <module>
TypeError: unbound method decode() must be called with BSON instance as first argument (got Binary instance instead)
>>> gotfield.decode()
Traceback (most recent call last):
  File "<stdin>",in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xb7 in position 0: ordinal not in range(128)
>>>

一旦我得到我的Python字符串,我就可以得到我的随机浮点数组.但是怎么样？