Python-python 的logging模块的日志级别设置不生效

Question

import logging
from logging.handlers import RotatingFileHandler

log_file = "log/log"
datetime_format = "%Y-%m-%d %H:%M:%S"
per_log_file_max_size = 10240
backup_count = 3

log_format = "%(asctime)s %(filename)s[line:%(lineno)d][%(levelname)s] %(message)s"

rotate_file_handler = RotatingFileHandler(log_file, maxBytes=per_log_file_max_size,
backupCount=backup_count)
rotate_file_handler.setLevel(logging.NOTSET)
formatter = logging.Formatter(log_format)
rotate_file_handler.setFormatter(formatter)
logging.getLogger('').addHandler(rotate_file_handler)

logging.debug('This is debug message')
logging.info('This is info message')
logging.warning('This is warning message')
logging.error('error')

输出：
2017-02-10 18:00:26,408 test.py[line:32][WARNING] This is warning message
2017-02-10 18:00:26,408 test.py[line:33][ERROR] error
2017-02-10 18:00:26,408 test.py[line:34][CRITICAL] critical

设置的日志级别是NOSET，实际上是WARNING
求解释：

Answer 1

import logging
from logging.handlers import RotatingFileHandler

log_file = "log/log"
datetime_format = "%Y-%m-%d %H:%M:%S"
per_log_file_max_size = 10240
backup_count = 3

log_format = "%(asctime)s %(filename)s[line:%(lineno)d][%(levelname)s] %(message)s"

rotate_file_handler = RotatingFileHandler(log_file, maxBytes=per_log_file_max_size,
backupCount=backup_count)
#rotate_file_handler.setLevel(logging.NOTSET)
formatter = logging.Formatter(log_format)
rotate_file_handler.setFormatter(formatter)
logging.getLogger('').addHandler(rotate_file_handler)
#在这里设置日志级别
logging.getLogger('').setLevel(logging.NOTSET)

logging.debug('This is debug message')
logging.info('This is info message')
logging.warning('This is warning message')
logging.error('error')