Space in cities is contested and public space is an important resource for the urban society in this context. Against the background of social justice, sufficient and fairly distributed public space in a city is to be strived for. In order to investigate the status quo of spatial distribution and availability of public spaces, this research develops a framework and Python script for identifying, categorizing and ultimately mapping public spaces using OSM data. The work is inspired by the historical Nolli map from Rome and the framework is applied to case studies in Vienna.