'Popen' 对象是不可订阅的 python 2.6答案

【问题标题】：'Popen' object is unsubscriptable python 2.6'Popen' 对象是不可订阅的 python 2.6
【发布时间】：2015-07-29 18:23:49
【问题描述】：

我是 Python 新手，不幸的是不知道如何在脚本中操作 vmstat。我有这段代码来获取 vmstat 的输出，经过大量研究后，我无法找到一种方法将其分配为 runqueue1 = sample1[0] 中的变量

    sample1 = Popen(['vmstat'] ,stdout=PIPE, stderr=PIPE)
    stdout, stderr = sample1.communicate()
    stdout.splitlines()[1]
    time.sleep(1)

    sample2 = Popen(['vmstat'] ,stdout=PIPE, stderr=PIPE)
    stdout, stderr = sample2.communicate()
    stdout.splitlines()[1]
    time.sleep(1)


    sample3 = Popen(['vmstat'] ,stdout=PIPE, stderr=PIPE)
    stdout, stderr = sample3.communicate()
    stdout.splitlines()[1]
    time.sleep(1)


    sample4 = Popen(['vmstat'] ,stdout=PIPE, stderr=PIPE)
    stdout, stderr = sample4.communicate()
    stdout.splitlines()[1]
    time.sleep(1)

    sample5 = Popen(['vmstat'] ,stdout=PIPE, stderr=PIPE)
    stdout, stderr = sample5.communicate()
    stdout.splitlines()[1]
    time.sleep(1)


    runqueue1 = sample1[0]
    runqueue2 = sample2[0]
    runqueue3 = sample3[0]
    runqueue4 = sample4[0]
    runqueue5 = sample5[0]

我遇到了这个回溯错误：

Traceback (most recent call last):
   File "./cputool", line 106, in <module>
      cputool()
   File "./cputool", line 98, in cputool
      runqueue1 = sample1[0]
TypeError: 'Popen' object does not support indexing

有没有人建议我如何以不同的方式安排它，以便它可以被索引/下标？除了 popen 之外还有什么其他方法可以获取 vmstat 的值，以便将它们分配给变量？

【问题讨论】：

你想要什么值？例如你期望sample1[0] 会返回什么？如果您正在寻找标准输出，您已经在进一步了解它：stdout, stderr = sample1.communicate()
mypipe = os.popen('find.exe . -type f ') myvar = mypipe.readlines()

标签： python indexing popen

【解决方案1】：

这里是一个简短的例子，我希望它能帮助你理解基础知识：

import subprocess
import time

# delay between update in seconds for vmstats
interval = 2
# create the process
proc = subprocess.Popen(
    ['vmstat', str(interval)],
    stdout=subprocess.PIPE, stderr=subprocess.PIPE
)

while True:
        try:
                # read operations are *blocking*
                # using readline() instead of read() or readlines()
                # we could start processing a line as soon it is received
                print 'output: %s' % proc.stdout.readline()
        except BaseException, error:
                proc.terminate()
                print 'terminated by %s' % error

【讨论】：