把需要的所有东西都封装在一个方法中：

def init_log(save_path, mode='w'):
    import logging

    logger = logging.getLogger()  # 不加名称设置root logger
    level = logging.DEBUG
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s: - %(message)s', datefmt='%Y-%m-%d %H:%M:%S')

    logger.setLevel(level)

    # 写入文件
    fh = logging.FileHandler(save_path, mode=mode)
    fh.setLevel(level)
    fh.setFormatter(formatter)

    # 使用StreamHandler输出到屏幕
    ch = logging.StreamHandler()
    ch.setLevel(level)
    ch.setFormatter(formatter)

    # 添加两个Handler
    logger.addHandler(ch)
    logger.addHandler(fh)
    return logger

调用时，只需要使用：

    logger = init_log('test_log.log')
	
	# 开始记录日志
    logger.debug('debug')
    logger.info('info')
    logger.warning('warning')
    logger.error('error')
    logger.critical('critial')

完整代码

def init_log(save_path, mode='w'):
    import logging

    logger = logging.getLogger()  # 不加名称设置root logger
    level = logging.DEBUG
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s: - %(message)s', datefmt='%Y-%m-%d %H:%M:%S')

    logger.setLevel(level)

    # 写入文件
    fh = logging.FileHandler(save_path, mode=mode)
    fh.setLevel(level)
    fh.setFormatter(formatter)

    # 使用StreamHandler输出到屏幕
    ch = logging.StreamHandler()
    ch.setLevel(level)
    ch.setFormatter(formatter)

    # 添加两个Handler
    logger.addHandler(ch)
    logger.addHandler(fh)
    return logger


if __name__ == '__main__':
    logger = init_log('test_log.log')
    logger.debug('debug')
    logger.info('info')
    logger.warning('warning')
    logger.error('error')
    logger.critical('critial')