Python日志记录:自定义记录器没有输出

Question

使用tutorial：https://realpython.com/python-logging/，我有以下脚本，只包含：

import logging

# Create a custom logger
logger = logging.getLogger(__name__)

# Create handlers
c_handler = logging.StreamHandler()
f_handler = logging.FileHandler('file.log')
c_handler.setLevel(logging.INFO)
f_handler.setLevel(logging.DEBUG)

# Create formatters and add it to handlers
c_format = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
f_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
c_handler.setFormatter(c_format)
f_handler.setFormatter(f_format)

# Add handlers to the logger
logger.addHandler(c_handler)
logger.addHandler(f_handler)

logger.debug('I am a debug msg')
logger.info('I am an info msg')

它应该将字符串同时写入控制台和文件('file.log')。文件已创建，bot没有任何内容。而且也没有输出到控制台。你知道是什么导致了这种情况吗，或者是缺少了什么？

Answer 1

您忘记设置记录器本身的详细级别：

import logging

# Create a custom logger
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG) # The logger still needs its verbose level

# Create handlers
c_handler = logging.StreamHandler()
f_handler = logging.FileHandler('file.log')
c_handler.setLevel(logging.INFO)
f_handler.setLevel(logging.DEBUG)

# Create formatters and add it to handlers
c_format = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
f_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
c_handler.setFormatter(c_format)
f_handler.setFormatter(f_format)

# Add handlers to the logger
logger.addHandler(c_handler)
logger.addHandler(f_handler)

logger.debug('I am a debug msg')
logger.info('I am an info msg')

另外，我建议根据每个处理程序来阻止你的代码，而不是类似的语法：

import logging

# Create a custom logger
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

# Streaming Handler
c_handler = logging.StreamHandler()
c_handler.setLevel(logging.INFO)
c_format = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
c_handler.setFormatter(c_format)
logger.addHandler(c_handler)

# File Handler
f_handler = logging.FileHandler('file.log')
f_handler.setLevel(logging.DEBUG)
f_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
f_handler.setFormatter(f_format)
logger.addHandler(f_handler)

logger.debug('I am a debug msg')
logger.info('I am an info msg')