Gather attributes from a list of subnets with terraform

main.tf

# terraform aws_subnet return multiple elements

data "aws_vpc" "main" {
  tags = {
    Name = "your-vpc"
  }
}

data "aws_subnet_ids" "main" {
  vpc_id = data.aws_vpc.main.id
}

data "aws_subnet" "main" {
  id = tolist(data.aws_subnet_ids.main.ids)[count.index]

  count = length(data.aws_subnet_ids.main.ids)
}

# then you can use them as data.aws_subnet.main.*.availability_zone