日志（Logging）系统的分级与自定义目标

import logging

# 设置日志级别
logging.basicConfig(level=logging.DEBUG)

# 创建日志记录器
logger = logging.getLogger(__name__)

# 记录不同级别的日志
logger.debug("This is a debug message")
logger.info("This is an info message")
logger.warning("This is a warning message")
logger.error("This is an error message")
logger.critical("This is a critical message")

import logging
import sqlite3

class DatabaseHandler(logging.Handler):
    def __init__(self, db_name):
        logging.Handler.__init__(self)
        self.db = sqlite3.connect(db_name)
        self.cursor = self.db.cursor()
        self.cursor.execute('''
            CREATE TABLE IF NOT EXISTS logs (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                level TEXT,
                message TEXT,
                timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
            )
        ''')
        self.db.commit()

    def emit(self, record):
        self.cursor.execute('''
            INSERT INTO logs (level, message) VALUES (?, ?)
        ''', (record.levelname, record.getMessage()))
        self.db.commit()

# 设置日志记录器
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

# 创建自定义日志处理器
db_handler = DatabaseHandler('logs.db')
logger.addHandler(db_handler)

# 记录日志
logger.debug("This log will be saved to the database")