I will show how to use Python and NVIDIA DALI to offload data preprocessing to the GPU in a Deep Learning workflow with just a few lines of code. I will discuss why and when this technique is beneficial and show speedups in real world examples. Attendees will learn how to use advanced features of the GPU like hardware accelerated image and video decoding or optical flow calculation using Python. After the talk attendees will be able to apply presented concepts to their own neural network training.