ExoData: A python package to handle large exoplanet catalogue data

Exoplanet science often involves using the system parameters of real exoplanets for tasks such as simulations, fitting routines, and target selection for proposals. Several exoplanet catalogues are already well established but often lack a version history and code friendly interfaces. Software that bridges the barrier between the catalogues and code enables users to improve the specific repeatability of results by facilitating the retrieval of exact system parameters used in articles results along with unifying the equations and software used. As exoplanet science moves towards large data, gone are the days where researchers can recall the current population from memory. An interface able to query the population now becomes invaluable for target selection and population analysis. ExoData is a Python interface and exploratory analysis tool for the Open Exoplanet Catalogue. It allows the loading of exoplanet systems into Python as objects (Planet, Star, Binary, etc.) from which common orbital and system equations can be calculated and measured parameters retrieved. This allows researchers to use tested code of the common equations they require (with units) and provides a large science input catalogue of planets for easy plotting and use in research. Advanced querying of targets is possible using the database and Python programming language. ExoData is also able to parse spectral types and fill in missing parameters according to programmable specifications and equations. Examples of use cases are integration of equations into data reduction pipelines, selecting planets for observing proposals and as an input catalogue to large scale simulation and analysis of planets. ExoData is a Python package available freely on GitHub. It’s open source and community contributions are encouraged. The package can be easily installed using pip install exodata, detailed setup information is provided within.系外行星科学（Exoplanet science）常需借助真实系外行星的系统参数，开展模拟、拟合流程以及观测提案的目标筛选等任务。目前已有多个成熟的系外行星目录，但大多缺乏版本历史记录与适配代码的友好接口。能够打通目录与代码之间壁垒的软件，可帮助研究者便捷获取论文成果中用到的精确系统参数，同时统一所用的计算公式与软件工具，进而提升研究结果的可复现性。随着系外行星科学迈向大数据时代，研究者仅凭记忆梳理当前行星族群的时代已一去不返，能够查询该行星族群的接口，如今已成为目标筛选与族群分析工作中不可或缺的工具。ExoData是一款面向开放系外行星目录（Open Exoplanet Catalogue）的Python接口与探索性分析工具，它支持将系外行星系统以对象（行星（Planet）、恒星（Star）、双星系统（Binary）等）的形式载入Python环境，进而可计算常见轨道与系统相关公式，并提取实测参数。这使得研究者可直接使用经过验证的、自带单位的常用计算公式代码库，并可获取海量行星科学输入目录，以方便绘图及研究应用。借助该数据库与Python编程语言，还可实现对目标天体的高级查询。此外，ExoData可解析光谱类型，并可根据可编程规范与计算公式补全缺失的系统参数。其典型应用场景包括：将计算公式集成至数据归算流程、为观测提案筛选目标行星，以及作为行星大规模模拟与分析的输入目录。ExoData是一款可在GitHub上免费获取的Python软件包，该软件为开源项目，欢迎社区贡献代码。可通过`pip install exodata`命令快速安装，详细安装说明已随包提供。