How to programmatically access fully rendered CFT

[ESattler]

For my use case, I would like to programmatically build the CFT and have it fully rendered without placeholders, without using the CLI.

For example, if I have as part of my stack

vpc = ec2.Vpc.from_lookup(self, "Vpc", vpc_name="My VPC Name")

If I have the code

MyStack(app, "CdfTestStack")
synth = app.synth()
template = synth.get_stack_by_name("CdfTestStack").template

If I run this python code as python3 app.py and output what is in the template, it gives me vpc-12345 as the VPC, which I believe is just a placeholder. It doesn't actually do the look up at that point.

It seems to me that the only way to get it to fully render is through running the CLI cdk synth and then it will properly use the credentials for a look up. Ideally I would like to do this programmatically as for my use case, I wanted to build the CFT as code and take the fully rendered CFT and pass it along to a boto3 call to actually do the creation of it.