python-3.x - 仅将最后一个 shell 命令的标准输出放入 Python 变量中

Question

这个问题在这里已经有了答案:





How to get the last N lines of a subprocess' stderr stream output?

(2 个回答)


9 个月前关闭。




prova.sh 包含:

#!/bin/bash
echo "Output that I don't want."
echo "Output that I don't want."
echo "Output that I don't want."
echo -e "Output that I want.\nI want this too.\
\nI want this too." #This is the last command of the bash script, which is what I'm looking for.

这个解决方案:

import subprocess
output = subprocess.check_output('./prova.sh', shell=True, text=True)
print(output, end='')

将所有 shell 命令的标准输出放在一个变量中:

Output that I don't want.
Output that I don't want.
Output that I don't want.
Output that I want.
I want this too.
I want this too.

但我只想要最后一个 shell 命令的标准输出:

Output that I want.
I want this too.
I want this too.

我怎样才能得到这个？
python 3.8.5
现有问题仅解决如何获得 N 行或类似问题。相比之下，我只想要最后一个命令的输出。

Answer 1

丢弃 Bash 脚本中先前命令的输出，因为在 Python 端无法识别哪个命令是哪个命令。

#!/bin/bash
echo "Output that I don't want." >/dev/null
echo "Output that I don't want." >/dev/null
echo "Output that I don't want." >/dev/null
echo -e "Output that I want.\nI want this too.\nI want this too." #This is the last command of the bash script, which is what I'm looking for.

另一种解决方案是将最后一个命令的输出写入文件:

# Modify the Bash script
import io, re
with io.open("prova.sh","r") as f:
    script  = f.read().strip()
    script  = re.sub(r"#.*$","",script).strip() # Remove comment
    script += "\x20>out.txt"                    # Add output file

with io.open("prova.sh","w") as f:
    f.write(script)

# Execute it
import subprocess
output = subprocess.check_output("./prova.sh", shell=True)
# print(output.decode("utf-8"))

# Get output
with io.open("out.txt","r") as f:
    print(f.read())