We introduce a Python open-source library for $\mathcal{X}$-armed bandit and online blackbox optimization named PyXAB. PyXAB contains the implementations for more than 10 $\mathcal{X}$-armed bandit algorithms, such as HOO, StoSOO, HCT, and the most recent works GPO and VHCT. PyXAB also provides the most commonly-used synthetic objectives to evaluate the performance of different algorithms and the various choices of the hierarchical partitions on the parameter space. The online documentation for PyXAB includes clear instructions for installation, straight-forward examples, detailed feature descriptions, and a complete reference of the API. PyXAB is released under the MIT license in order to encourage both academic and industrial usage. The library can be directly installed from PyPI with its source code available at https://github.com/WilliamLwj/PyXAB

翻译：我们介绍一个用于$\mathcal{X}$-臂赌博机及在线黑箱优化的Python开源库PyXAB。PyXAB包含了10余种$\mathcal{X}$-臂赌博机算法的实现，例如HOO、StoSOO、HCT以及最新的GPO和VHCT等工作。PyXAB还提供了最常用的合成目标函数以评估不同算法的性能，以及参数空间上层次划分的多种选择。PyXAB的在线文档包含了清晰的安装说明、直观的示例、详细的功能描述以及完整的API参考。PyXAB采用MIT许可证发布，旨在鼓励学术和工业应用。该库可直接通过PyPI安装，其源代码可在https://github.com/WilliamLwj/PyXAB获取。