将python脚本中的变量解析为shell [重复]答案

【问题标题】：Parsing a variable inside a python script to shell [duplicate]将python脚本中的变量解析为shell [重复]
【发布时间】：2020-12-03 20:59:54
【问题描述】：

大家好，我是使用 python 编写的新手，我正在尝试如何将变量解析到 shell 中。例如；

#!/usr/python3
import os
import subprocess

sometext = 'Hello World'

os.system("echo $sometext")

这不会返回任何内容，我假设这不会正确解析。但解释了我想要做什么。

我做了一些挖掘并尝试替换最后一行

#!/usr/python3
import os
import subprocess

sometext = 'Hello World'

subprocess.call('echo {sometext}')

这会吐出以下错误；

Shell % python3 pingtest.py
Traceback (most recent call last):
  File "pingtest.py", line 12, in <module>
    subprocess.call('echo {sometext}')
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/subprocess.py", line 340, in call
    with Popen(*popenargs, **kwargs) as p:
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/subprocess.py", line 854, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/lib/python3.8/subprocess.py", line 1702, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'echo {sometext}'

【问题讨论】：

一个不明显的复杂情况是，如果没有shell=True，Python 将寻找一个名称为'echo {sometext}' 的可执行文件。如果你真的需要shell=True，添加它；但对于大多数任务，你probably want to avoid it if you can.

标签： python python-3.x bash parsing subprocess

【解决方案1】：

#!/usr/bin/python3
import subprocess
sometext = 'Hello World'
subprocess.call(["echo", sometext])

【讨论】：