dune-gdt is a software library for building applications using grid-based numerical methods. It is a generic discretization toolbox and provides building blocks - like local operators, local evaluations, local assemblers - for discretization methods and suitable discrete function spaces. It is realized as a DUNE module and leverages newer C++ language features and the dune-xtensions to provide an easy-to-use and mathematically sound API. A subset of the API is exposed as Python-bindings using pybind11, and easily available as wheels on pypi.