What is the difference between pytorch-quantization and torch.ao.quantization

Thank you very much for your reply. well I think what you describe is the difference between torch.quantization and torch.ao.quantization, which is similar in this answer. I am not sure that torch.quantization/torch.ao.quantization and pytoch-quantization whether be two different packages(the former come from pytorch, the letter come from nvidia?), they can both be used to quantization, just api not common?