They require at least Python 3.6. (If you're looking for the code and examples from the first edition, that's in the first-edition folder.) If you want to use the code, you should be able to clone the ...

CuPy is a NumPy/SciPy-compatible array library for GPU-accelerated computing with Python. CuPy acts as a drop-in replacement to run existing NumPy/SciPy code on NVIDIA CUDA or AMD ROCm platforms. CUDA ...