No, model.parameters() will list all registered parameters. E.g. if you are using a custom module and assign a parameter as
self.my_param = nn.Parameter(torch.randn(1))

it will also be listed in model.parameters().
What is your use case that you would like to check, if the module has weight as a parameter?
weight.data refers to the underlying data tensor. If you manipulate it, Autograd won’t be able to track this operation, which might result in wrong calculations. Therefore I would recommend to avoid using the .data attribute.