Question

从subprocess.run()上的文档中的示例看来，

似乎不应该有任何输出

subprocess.run(["ls", "-l"])  # doesn't capture output

然而，当我在python shell中尝试它时，列表被打印出来。我想知道这是否是默认行为以及如何抑制run()的输出。

Answer 1

要取消输出，您可以重定向到/dev/null

import os
import subprocess

with open(os.devnull, 'w') as devnull:
    subprocess.run(['ls', '-l'], stdout=devnull)
    # The above only redirects stdout...
    # this will also redirect stderr to /dev/null as well
    subprocess.run(['ls', '-l'], stdout=devnull, stderr=devnull)
    # Alternatively, you can merge stderr and stdout streams and redirect
    # the one stream to /dev/null
    subprocess.run(['ls', '-l'], stdout=devnull, stderr=subprocess.STDOUT)

如果您想捕获输出（以后使用或解析），您需要使用subprocess.PIPE

import subprocess
result = subprocess.run(['ls', '-l'], stdout=subprocess.PIPE)
print(result.stdout)

# To also capture stderr...
result = subprocess.run(['ls', '-l'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
print(result.stdout)
print(result.stderr)

# To mix stdout and stderr into a single string
result = subprocess.run(['ls', '-l'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
print(result.stdout)

Answer 2

ex：捕获ls -a

的输出

import subprocess
ls = subprocess.run(['ls', '-a'], capture_output=True, text=True).stdout.strip("\n")
print(ls)

如何抑制subprocess.run（）的输出？

2 个答案: