python学习：异常处理、with用法以及utf8中文显示

# !/usr/bin/env python# -*-coding:utf8-*-# 为文件中每行的开头添加行号def addLineNumberForFile(srcFilePath, dstFilePath):if srcFilePath == dstFilePath:raise NameError('Invalid arguments, ' + 'p1 = ' + srcFilePath + ', p2 = ' + dstFilePath)with open(srcFilePath) as srcfd:lineNum = 0with open(dstFilePath, 'w') as dstfd:for line in srcfd.readlines():lineNum += 1dstfd.write(str(lineNum) + "\t" + line)# 单元测试if __name__ == '__main__':srcFilePath = 'data.txt'dstFilePath = 'data_latest.txt'try:addLineNumberForFile(srcFilePath, dstFilePath)print('Success to add line number for the file named ' + srcFilePath)print('The result file is ' + dstFilePath)except NameError as nError:print nError

中文有乱码，还可以做下面的设置：

import sysreload(sys)sys.setdefaultencoding('utf-8')