Question

我正在编写一个Python命令行程序。

有一个主要的Python脚本文件，作为入口点。当用户运行此脚本时，它将执行一些外部Python脚本文件。外部Python脚本文件也可以执行其他外部Python脚本文件。外部文件的数量是可变的。

Python脚本将使用以下命令执行外部Python脚本：

p = subprocess.Popen(args)

or

p = subprocess.call(args)

当我在终端窗口中运行主Python脚本时，它将在屏幕上运行时打印实时日志消息。现在，我想从主Python脚本调用的所有外部Python脚本中获取所有日志消息，并将其打印到同一个终端窗口（我用来运行主脚本的终端窗口）。

例如，下面是脚本执行的顺序：

1.Main-script
    |
    2.Layer-1-script-1
        |
        3.Layer-2-script-1
        |
        4.Layer-2-script-2
        |
    5.Layer-1-script-2
    |
    6.Layer-1-script-3
    |
7.Main-script(continued)

当我在终端窗口中运行主脚本时，我是否可以在终端窗口上获得如下所示的实时日志消息？

[time-hh-mm-ss][log message from main script]Script is running..
[time-hh-mm-ss][log message from main script]Calling script layer-1-script-1..
[time-hh-mm-ss][log message from layer-1-script-1]Script is running..
[time-hh-mm-ss][log message from layer-1-script-1]Calling script layer-2-script-1..
[time-hh-mm-ss][log message from layer-2-script-1]Script is running..
[time-hh-mm-ss][log message from layer-2-script-1]Calling script layer-2-script-2..
[time-hh-mm-ss][log message from layer-2-script-2]Script is running..
[time-hh-mm-ss][log message from layer-2-script-2]Calling script layer-1-script-2..
[time-hh-mm-ss][log message from layer-1-script-2]Script is running..
[time-hh-mm-ss][log message from layer-1-script-2]Calling script layer-1-script-3..
[time-hh-mm-ss][log message from layer-2-script-3]Script is running..
[time-hh-mm-ss][log message from main script]Back to main script. Script is running..

我可以在终端窗口中获得上面的real time log messages吗？

Answer 1

如果您依赖subprocess模块，那么您只能通过subprocess.PIPE进行通信，以便从子流程中收集标准输出和标准错误。因此，使子进程将其日志输出写入stdout / err，并通过管道将子进程连接到父进程。通过这样做，您基本上可以将子进程'stdout打印到父进程'stdout。

Answer 2

如果您可以控制所有Python脚本，那么您可以使用multiprocessing而不是subprocess来执行以下操作：

<强> test.py ：

import logging
import test2
import multiprocessing as mp

logger = mp.get_logger()

def main():
    logger.info('Script is running')
    logger.info('Calling script test2')
    proc = mp.Process(target = test2.main)
    proc.start()
    proc.join()

if __name__ == '__main__':
    formatter = logging.Formatter('[%(asctime)s] [%(filename)s]: %(message)s',
                                  datefmt = '%H:%M:%S')
    handler = logging.StreamHandler()
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    logger.setLevel(logging.INFO)    
    main()

<强> test2.py：

import multiprocessing as mp

logger = mp.get_logger()

def main():
    logger.info('Script is running...')

运行test.py会产生

[11:36:50] [test.py]: Script is running
[11:36:50] [test.py]: Calling script test2
[11:36:50] [util.py]: child process calling self.run()
[11:36:50] [test2.py]: Script is running...
[11:36:50] [util.py]: process shutting down
[11:36:50] [util.py]: process exiting with exitcode 0
[11:36:50] [util.py]: process shutting down

如何将外部模块的日志消息打印到主Python模块的终端窗口？

2 个答案: