python 2.7 : Using subprocess and a For Loop to output results

Question

我有一个脚本可以检查多个主机的字符串模式(在这种情况下它会寻找“平台”。我想添加到这个程序中，让它在找不到该搜索模式时打印一些东西。有人可以帮忙吗指引我正确的方向？例如，如果它没有找到任何“平台”，那么它不会打印出来，而是打印“我们找不到那个主机!”

#!/usr/bin/python

import commands, os, string
import sys
import fileinput
import subprocess
from subprocess import Popen, PIPE
import shlex


nodename = raw_input("Enter the hostname: ")

hostname=['hostA', 'hostB', 'hostC']

for i in hostname:
    print "Checking Host List..."

    cmd = "ls -l" + hostname
    args = shlex.split(cmd)

    p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out, err = p.communicate()

    if out.find("Platform") > -1:
        print out
        break

Answer 1

类似的东西应该可以完成工作:

#!/usr/bin/python
import commands, os, string
import sys
import fileinput
import subprocess
from subprocess import Popen, PIPE
import shlex


nodename = raw_input("Enter the hostname: ")

hostname=['hostA', 'hostB', 'hostC']

for i in hostname:
    print "Checking Host List..."

    cmd = "ls -l "+i
    args = shlex.split(cmd)

    p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out, err = p.communicate()
    print out

    if out.find("Platform") > -1:
        print out
        break

    if i == hostname[-1]:
        print "We could not find that host!"

hostname[-1] 实际上是 hostname 列表最后一个元素的快捷方式。因此，只有当您到达 hostname 列表的最后一个元素并且它不包含 "Platform" 时，您才会进入最后一个 if block 。