Running Cuda on CPU only

Hello,

I am quite new to cuda, and I have a tried to run a deep-learning project written in python, but I get this error:
RuntimeError: Found no NVIDIA driver on your system. Please check that you have an NVIDIA GPU and installed a driver from http://www.nvidia.com/Download/index.aspx.

The line which causes the error is this one: modelVars[‘model’] = modelVars[‘model’].cuda()
I have no NVIDIA driver on my computer, and I tried running this with --gpu_ids -1, for it to run only on CPU, but I still get the error. Is there any way I can run it only on CPU or cuda always requiers a GPU ?

Thank you.