python2.x
In [1]: u'你好'
Out[1]: u'\u4f60\u597d'
In [2]: 'jafldsjjaggh'
Out[2]: 'jafldsjjaggh'
编码
In [5]: s.encode('utf8')
Out[5]: '\xe4\xbd\xa0\xe5\xa5\xbd'
In [6]: print '\xe4\xbd\xa0\xe5\xa5\xbd'
你好
In [7]: '\xe4\xbd\xa0\xe5\xa5\xbd'.decode('utf8')
Out[7]: u'\u4f60\u597d'
解码
In [8]: print '\xe4\xbd\xa0\xe5\xa5\xbd'.decode('utf8')
你好
python2.x读取文件
In [10]: f = open('py2.txt','w')
In [11]: f
Out[11]: <open file 'py2.txt', mode 'w' at 0xb69e2c28>
In [12]: s = u'你好'
In [13]: f.write(s.encode('gbk'))
In [14]: cat py2.txt
In [15]: f.close()
In [16]: cat py2.txt
ţº
In [17]: f = open('py2.txt','r')
In [18]: t = f.read()
In [19]: t
Out[19]: '\xc4\xe3\xba\xc3'
In [20]: t.decode('gbk')
Out[20]: u'\u4f60\u597d'
In [21]: print t.decode('gbk')
你好
python3.x
python3省去了在python2.x中手工编码和解码的工作
在python3.x中表示byte
In [8]: b'eajfsdjfjl'
Out[8]: b'eajfsdjfjl'
在python3.x中表示unicode字符串
In [9]: '你好'
Out[9]: '你好'
In [19]: f = open('py3.txt','wt',encoding='utf8')
In [20]: f
Out[20]: <_io.TextIOWrapper name='py3.txt' mode='wt' encoding='utf8'>
In [21]: f.write('我爱编程！')
Out[21]: 5
In [23]: f.close()
In [24]: f = open('py3.txt','rt',encoding='utf8')
In [25]: f.read()
Out[25]: '我爱编程！'
In [26]: s = f.read()
In [27]: s
Out[27]: ''
重置指针到文件头部初始位置
In [28]: f.seek(0)
Out[28]: 0
In [29]: s = f.read()
In [30]: print(s)
我爱编程！
