python中的bash : sed未终止的命令

Question

下面的命令在bash中运行良好。

/folk/vlm/commandline/./vlmTool find -l all | grep -e "^Target ID" -e "City" -e "Zone" | sed "s#.*City.*#&\n#g" > new.txt

但是在python中，当我试图执行相同的命令时，我得到：

['sed', 's#.*City.*#&\n#g']
**sed: -e expression #1, char 12: unterminated `s' command**

代码：

#!/usr/local/bin/python -tt

import subprocess
import shlex
cmd = '/folk/vlm/commandline/./vlmTool find -l all | grep -e "^Target ID" -e "City" -e "Zone" | sed "s#.*City.*#&\n#g" > new.txt'
cmd2= "/folk/vlm/commandline/./vlmTool find -l all"
args1 = shlex.split(cmd2)
cmd3 = 'grep -e "^Target ID" -e "City" -e "Zone"'
args2 = shlex.split(cmd3)
cmd4 =  'sed "s#.*City.*#&\n#g"'
args3 = shlex.split(cmd4)
print args3
p1 = subprocess.Popen(args1, stdout=subprocess.PIPE)
p2 = subprocess.Popen(args2, stdin=p1.stdout, stdout=subprocess.PIPE)
p3 = subprocess.Popen(args3, stdin=p2.stdout, stdout=subprocess.PIPE)
p1.stdout.close()
p2.stdout.close()
output = p3.communicate()[0]

Answer 1

在python中，\n序列被理解为换行符的转义序列；因此sed认为s命令已经完成并启动了一个新命令。要获得字符串中包含的反斜杠，可以像...\\n...那样转义它，或者使用原始字符串：r's#.*City.*#&\n#g'