Extensions to the Python Logging module: adding custom functionality

python The Logging module is a powerful tool for recording events and errors in the program. By extending this module, you can add custom functionality to improve logging logging capabilities and simplify debugging and error handling. This article will guide you on how to extend the Logging module to meet your specific needs.

Extension methods

There are two main ways to extend the Logging module:

• Create a new logger: You can use logging.getLogger() to create a new logger and configure it with custom levels and formatters.
• Using Logger Extensions: You can use logging.LoggerAdapter() to create a logger extension that can add custom functionality to its parent logger.

Add custom level

You can use the logging.addLevelName() function to add a custom level. This allows you to define the importance of the new level, making it higher or lower than the existing level. For example, you could add a level called "TRACE" with a higher importance than DEBUG.

import logging

# 添加自定义级别
logging.addLevelName(5, "TRACE")

Use custom level

After adding a custom level, you can use it to log messages. Use the logger.log() function and specify a custom level:

# 使用自定义级别
logger.log(5, "自定义跟踪消息")

Create a custom formatter

The format of log messages can be changed by creating a custom formatter class. This class must implement the f<strong class="keylink">ORM</strong>at() method, which formats the logging message.

import logging

# 创建自定义格式化程序类
class MyFormatter(logging.Formatter):
def format(self, record):
# 自定义格式化代码
return f"{record.levelname}: {record.message}"

Use a custom formatter

After creating a custom formatter, you can attach it to the logger:

# 使用自定义格式化程序
logger.handlers[0].setFormatter(MyFormatter())

Using Logger Extension

Logger extensions allow you to add custom functionality to existing loggers. You can use logging.LoggerAdapter() to create a logger extension and provide it with additional contextual information or handlers.

import logging

# 创建新的日志记录器
logger = logging.getLogger("my_logger")

# 创建日志记录器扩展
adapter = logging.LoggerAdapter(logger, {"extra_info": "额外信息"})

# 使用日志记录器扩展
adapter.info("扩展日志消息")

Using the logger extender

The logger extender also allows you to add additional contextual information to log messages. This information can be accessed through the extra dictionary.

# 从日志记录器扩展器访问额外信息
print(adapter.extra["extra_info"])

Custom handler

In addition to extending the Logging module, you can also create custom handlers to handle logging messages. Custom handlers allow you to control how logging messages are handled, such as via email or Slack notifications.

import logging

# 创建自定义处理程序类
class MyHandler(logging.Handler):
def emit(self, record):
# 自定义处理逻辑
pass

# 将自定义处理程序添加到日志记录器
logger.addHandler(MyHandler())

Summarize

Extensions Python The Logging module allows you to enhance logging functionality by adding custom levels, formatters, handlers, and expanders. By extending this module, you can simplify debugging, improve error handling, and have a more comprehensive logging experience.

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