在标准输出上显示 INFO 级 python 日志而不更改源代码

Question

If a module whose source code I can't change says something like:

# foo.py
import logging

logging.info('Hello world')

How can I see the logs while running

$ python foo.py

from my POSIX-compliant terminal?

All the answers I can find about this involve changing the source code.

The docs are pretty clear about logging WARN-level and above:

The INFO message doesn't appear because the default level is WARNING.

But I can't easily see how to change that default.

Answer 1

Run the script with an incantation that preconfigures logging for you (now 100% more Python3 compatible).

$ cat foo.py
import logging
logging.info('Hello world')

$ python3 -c 'import logging,sys,runpy;logging.basicConfig(level=logging.INFO,stream=sys.stdout);runpy.run_path("foo.py")'
INFO:root:Hello world
~/Desktop

Not memorable enough?

To make it more memorable, you can wrap things in a please_log.py . Some sys.argv finagling is required.

please_log.py

import logging, sys, runpy
script = sys.argv.pop(1)
logging.basicConfig(level=logging.INFO, stream=sys.stdout)
runpy.run_path(script)

foo.py

import logging
import sys

logging.info('Hello world: %s', sys.argv)

output

$ python3 please_log.py foo.py
INFO:root:Hello world: ['foo.py']