zlib 解压头检查错误
我在处理一个字典的时候遇到了问题，我想把它压缩后存储到Postgres数据库里。我可以顺利地压缩和解压这个字典，但当我把它插入数据库后，再取出来尝试解压时却出现了错误：
zlib.error: Error -3 while decompressing data: incorrect header check
这是我写的一个测试脚本，用来模拟所有的步骤：
import zlib
import cPickle
import psycopg2
try:
db = psycopg2.connect( database='*****', user='*****', password='*****',host='******')
cursor = db.cursor()
except:
print 'no db'
atom_id = 166503
params = {'submission': 'RVBV4SXLVVDNAAKIG2LIJKZQ', 'campaign': 'p3percybot', 'dob': '2011-03-11', 'rndrpath': '/mnt/webservices/store/p3percybot/rndr/2011-03-11/RVBV4SXLVVDNAAKIG2LIJKZQ', 'outpath': '/mnt/webservices/store/p3percybot/out/2011-03-11/RVBV4SXLVVDNAAKIG2LIJKZQ', 'srcpath': '/mnt/webservices/store/p3percybot/src', 'root': '/mnt/webservices/store', 'inpath': '/mnt/webservices/store/p3percybot/in/2011-03-11/RVBV4SXLVVDNAAKIG2LIJKZQ'}
print params
params_list = []
for k in params :
param_name = k
param_value = cPickle.dumps(params[k])
param_value = zlib.compress(param_value,9)
param_value = buffer(param_value)
params_list.append((param_value,atom_id, param_name))
print params_list
sql = 'UPDATE atomparams set value = %s where atomid=%s and name=%s'
cursor.executemany(sql, (params_list))
sql = 'SELECT name, value FROM atomparams WHERE atomid=%s'
cursor.execute(sql, (atom_id,))
result = cursor.fetchall()
print '\n-----------------result-----------------'
print result
for data in result:
print data[0]
data_string = zlib.decompress(data[1])
print data_string
如果有人能给我一些建议，为什么在数据库里会出现这种问题，我会非常感激。我想说明一下，存储这个值的字段类型是bytea。
提前谢谢大家！