python命令替换linux命令

Question

我正在尝试使用命令替换从python脚本构建linux命令，但是无法使用以下简单示例：

LS="/bin/ls -l"
FILENAME="inventory.txt"

cmd = "_LS _FILENAME "
ps= subprocess.Popen(cmd,shell=True,stdout=subprocess.PIPE,stderr=subprocess.STDOUT)
output = ps.communicate()[0]
print output

谢谢！

JB

Answer 1

使用string substitution：

cmd = '{} {}'.format(LS, FILENAME)

或（在Python2.6中）：

cmd = '{0} {1}'.format(LS, FILENAME)

---

import subprocess
import shlex

LS="/bin/ls -l"
FILENAME="inventory.txt"

cmd = '{} {}'.format(LS, FILENAME)    
ps = subprocess.Popen(shlex.split(cmd),
                      stdout = subprocess.PIPE,
                      stderr = subprocess.STDOUT)
output, err = ps.communicate()
print(output)

---

或者，使用sh module：

import sh
FILENAME = 'inventory.txt'
print(sh.ls('-l', FILENAME, _err_to_out=True))