terraform and variables in modules

I have this file in a folder "modules/network/variables.tf" :

variable "iam_profile" {
  description = "IAM profile"
  default     = "ec2_profile"
}

and I can't get the variable from this main tf file :`

module "network" {
  source = "./modules/network" 
}
output "test1" {
  value = "${module.network.iam_profile}" => error : This object does not have an attribute named "iam_profile"
}
output "test2" {
  value = "${module.network.var.iam_profile}" => error  : This object does not have an attribute named "var"
}

Any idea why I have errors after terraform init and apply?

Depending on what you really need/want, the answer will be different. If something called iam_profile needs to be created by the module network, then you need to have an output defined in the module as well. If you want to access a variable from the module, that is not possible. To use the syntax you have shown in the question, you need to do the following in the outputs.tf of the module:

output "iam_profile" {
  value = var.iam_profile
}

Then, in the root module (i.e, the code where you want the output of the module), you would do the following:

module "network" {
  source = "./modules/network" 
}
output "test1" {
  value = module.network.iam_profile
}