python子进程打印和存储标准输出

Question

我正在学习 python 并编写一个小脚本。我需要将我的输出保存在一个文件中，并且还要在屏幕上打印输出。我尝试了各种方法，例如stdout=subprocess.PIPEi 无法确定输出到两者。请原谅我这个愚蠢的问题`

#!/usr/bin/python
import os
import subprocess
with  open('/root/test/testfile') as f , open('aaa.txt',"w") as final:
    content =  f.read().splitlines()
    for x in content:
            result= subprocess.Popen(['grep',x,'/news/today/night/logs'],stdout=final)

Answer 1

看起来您只是使用子进程来运行 grep，但 python 也可以对字符串进行类似 grep 的匹配。该程序将读取“testfile”中的行，然后从“log”中写出包含 testfile 行的行。 “testfile”中第一行的所有日志匹配都将在第二行的匹配之上，等等......并且匹配多个testfile行的日志行将输出多次。

此代码假定您没有匹配正则表达式。

#!/usr/bin/python

# assuming logs is not too big, you could read it into memory once
# with open('/news/today/night/logs') as logfile:
#     logs = list(logfile)
    
with  open('/root/test/testfile') as f , open('aaa.txt',"w") as final:
    for wanted in f:
        wanted = wanted.strip()
        with open('/news/today/night/logs') as logs:
            for log in logs:
                if wanted in log:
                    print(log, end='')
                    final.write(log)

Answer 2

试试这个：

#!/usr/bin/python
import os

with open('/root/test/testfile') as f, open('/root/test/aaa.txt',"a") as final:
    content = f.read().splitlines()
    for line in content:
        if "/news/today/night/logs" in line:
            print(line)
            final.write(line)

我让你的 aaa.txt 文件追加而不是写入。