我试图在Python中进行系统调用,并将输出存储为我可以在Python程序中操作的字符串。

#!/usr/bin/python
import subprocess
p2 = subprocess.Popen("ntpq -p")

我尝试了一些事情,包括这里的一些建议:

检索subprocess.call()的输出

但运气不好。


当前回答

Python 2: http://docs.python.org/2/library/subprocess.html#subprocess.Popen

from subprocess import PIPE, Popen

command = "ntpq -p"
process = Popen(command, stdout=PIPE, stderr=None, shell=True)
output = process.communicate()[0]
print output

在Popen构造函数中,如果shell为True,则应该将命令作为字符串而不是序列传递。否则,只需将命令拆分为一个列表:

command = ["ntpq", "-p"]
process = Popen(command, stdout=PIPE, stderr=None)

如果你还需要读取标准错误到Popen初始化中,你应该将stderr设置为PIPE或STDOUT:

command = "ntpq -p"
process = subprocess.Popen(command, stdout=PIPE, stderr=PIPE, shell=True)
output, error = process.communicate()

注意:从Python 2.7开始,你可以/应该利用subprocess。# subprocess.check_output check_output (https://docs.python.org/2/library/subprocess.html)。


Python 3: https://docs.python.org/3/library/subprocess.html#subprocess.Popen

from subprocess import PIPE, Popen

command = "ntpq -p"
with Popen(command, stdout=PIPE, stderr=None, shell=True) as process:
    output = process.communicate()[0].decode("utf-8")
    print(output)

注意:如果你的目标只是Python版本高于或等于3.5,那么你可以/应该利用subprocess.run (https://docs.python.org/3/library/subprocess.html#subprocess.run)。

其他回答

 import os   
 list = os.popen('pwd').read()

在这种情况下,列表中只有一个元素。

这对我来说非常合适:

import subprocess
try:
    #prints results and merges stdout and std
    result = subprocess.check_output("echo %USERNAME%", stderr=subprocess.STDOUT, shell=True)
    print result
    #causes error and merges stdout and stderr
    result = subprocess.check_output("copy testfds", stderr=subprocess.STDOUT, shell=True)
except subprocess.CalledProcessError, ex: # error code <> 0 
    print "--------error------"
    print ex.cmd
    print ex.message
    print ex.returncode
    print ex.output # contains stdout and stderr together 

对于python 3.5,我根据前面的回答提出了函数。原木可能被移除,但它很好

import shlex
from subprocess import check_output, CalledProcessError, STDOUT


def cmdline(command):
    log("cmdline:{}".format(command))
    cmdArr = shlex.split(command)
    try:
        output = check_output(cmdArr,  stderr=STDOUT).decode()
        log("Success:{}".format(output))
    except (CalledProcessError) as e:
        output = e.output.decode()
        log("Fail:{}".format(output))
    except (Exception) as e:
        output = str(e);
        log("Fail:{}".format(e))
    return str(output)


def log(msg):
    msg = str(msg)
    d_date = datetime.datetime.now()
    now = str(d_date.strftime("%Y-%m-%d %H:%M:%S"))
    print(now + " " + msg)
    if ("LOG_FILE" in globals()):
        with open(LOG_FILE, "a") as myfile:
            myfile.write(now + " " + msg + "\n")

在Python 2.7或Python 3中

不用直接创建Popen对象,你可以使用subprocess.check_output()函数将命令的输出存储在字符串中:

from subprocess import check_output
out = check_output(["ntpq", "-p"])

在Python 2.4-2.6中

使用沟通方法。

import subprocess
p = subprocess.Popen(["ntpq", "-p"], stdout=subprocess.PIPE)
out, err = p.communicate()

出去是你想要的。

关于其他答案的重要提示

注意我是如何传入命令的。“ntpq -p”示例引出了另一个问题。由于Popen不调用shell,因此可以使用命令和选项的列表- ["ntpq", "-p"]。

import subprocess
output = str(subprocess.Popen("ntpq -p",shell = True,stdout = subprocess.PIPE, 
stderr = subprocess.STDOUT).communicate()[0])

这是一条直线解