如何创建一个类来帮助我记录我的应用程序用户活动？(整洁编码和代码重构问题)

# 定义一个日志记录接口
class ActivityLoggerInterface:
    def logActivity(self, activity: str):
        pass

    def getActivityCount(self) -> int:
        pass

# UserActivityLogger 类实现了日志记录接口
class UserActivityLogger(ActivityLoggerInterface):
    def __init__(self, file_path: str, file_name: str):
        self.log_file = file_path + '/' + file_name

    def logActivity(self, activity: str):
        with open(self.log_file, 'a') as f:
            f.write(activity + '\n')

    def getActivityCount(self) -> int:
        count = 0
        with open(self.log_file, 'r') as f:
            for line in f:
                count += 1
        return count

# 使用示例
logger = UserActivityLogger('/path/to/log', 'user_activity.log')
logger.logActivity('UserA logged in')
logger.logActivity('UserB performed an action')

activity_count = logger.getActivityCount()
print("Total activity count:", activity_count)