The ArcGIS Python API is a powerful, modern and easy to use Pythonic API for GIS professionals, developers, org administrators, content publishers and anyone with access to a Web GIS (which could be an ArcGIS Online organization or an ArcGIS Portal) to leverage the Python ecosystem and automate their workflows using scripts.  The API integrates well with the Jupyter Notebook http://jupyter.org/ and the SciPy stack, enabling academics, data scientists and GIS analysts to share programs and reproducible research with others.