python unicode编码转换

>>> a=u'中国'
>>> a
u'\u4e2d\u56fd'
>>> print a
中国

>>> print len(a)
2



>>> str=a.encode('gb2312')  #以gb2312编码对unicode对像进行编码
>>> str
'\xd6\xd0\xb9\xfa'
>>> print str
中国
>>> print len(str)
4
>>>


>>> print str.decode('gb2312')  以gb2312编码对字符串str进行解码，以获取unicode
中国
>>> print len(str.decode('gb2312'))  
2
>>>


#!/usr/bin/env python
# -*- coding: utf-8 -*-


import cx_Oracle
from pprint import pprint
import csv
import time
import re
import binascii
conn = cx_Oracle.connect('system/oracle@192.168.137.2/serv')
cursor = conn.cursor()
table_name="t300"
owner="system"
xsql='select process,sid from t300'
col=[]
r = cursor.execute(xsql)
for col in r:
    #print col[0].decode('gbk')
    if col[0].decode('gbk')==u'测试环境':
        print col[0].decode('gbk')
        print col[1]
        print 1111
        print len(col[0].decode('gbk'))
        print len('测试环境')
        print len(u'测试环境')

C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/oracle/t1.py
测试环境
987789
1111
4
12
4