Python logger is not printing debug messages, although it is set correctly

I have the following code, where I just want to play around with the logging module using contextmanager.

from contextlib import contextmanager
import logging

@contextmanager
def log_level(level, name):
    logger = logging.getLogger(name)
    old_level = logger.getEffectiveLevel()
    print('log_level.old_level: ' + str(old_level))
    logger.setLevel(level)
    print('log_level.new_level: ' + str(logger.getEffectiveLevel()))
    try:
        yield logger
    finally:
        logger.setLevel(old_level)

if __name__ == '__main__':

    with log_level(logging.DEBUG, 'my-log') as logger:
        print('__main__.log_level.logger.level: ' + str(logger.getEffectiveLevel()))
        logger.debug('Debug with logger: will print')
        logger.warning('Warning')
        print('__main__.log_level.logger.level: ' + str(logger.getEffectiveLevel()))
    print('__main__.logger.level: ' + str(logger.getEffectiveLevel()))

As one can see, inside the main.log_level, the logger level should be DEBUG and it should print the message 'Debug with logger: will print'. However, when I run the code, this debug message does not print. Looking the prints of the code, It says that the logger has DEBUG level while inside log_level, and that the level goes back to WARNING when it exits log_level. Here it is my output, when executing with python 3:

log_level.old_level: 30
log_level.new_level: 10
__main__.log_level.logger.level: 10
Warning
__main__.log_level.logger.level: 10
__main__.logger.level: 30

I would like some help to understand why logger.debug('Debug with logger: will print') is not printing.