学步园

# !/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 = 0
		with open(dstFilePath, 'w') as dstfd:
			for line in srcfd.readlines():
				lineNum += 1
				dstfd.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 sys
reload(sys)
sys.setdefaultencoding('utf-8')