##将文本中的name=配置项值更新为name=newvalue
import re
import os
p=re.compile(r'(^name)=(.+)')
f=file('d://soft/list.txt','r')
f2=file('d://soft/list3.txt','w')
while True:
line=f.readline()
if len(line)==0:
break
line=p.sub(r'\1=newvalue',line)
#line=p.sub(r'\1=newfff',f.readline())
print line
f2.write(line)
f2.close()
f.close()
if os.path.exists('d://soft/list.txt.bak2'):
os.remove('d://soft/list.txt.bak2');
os.rename('d://soft/list.txt', 'd://soft/list.txt.bak2')
os.rename('d://soft/list3.txt', 'd://soft/list.txt')