Hello @nick.lloyd, the logic of expected_ip_cidr = "10.0.0.0/16"
is available in Terraform, not in XO. But as you're building a Python script you could implements there the same logic: define a variable for your expected cidr, and poll the IP of the VM until it matches.
Else, as you're using Python, you might be interested by the Pulumi Python SDK we will release this month. It allows you to easily define your infrastructure as code like with Terraform, but using Python
There you will also have the expected_ip_cidr param, in Python..
https://pypi.org/project/pulumi-xenorchestra/
https://github.com/vatesfr/pulumi-xenorchestra/
https://www.pulumi.com/product/infrastructure-as-code/