Reference custom params file in dvc template / dict unpacking

Question

The examples for template referencing and dict unpacking assume the default params.yaml file.

So if for example I have the following params.yaml

group:
  param_one: some_value

We can do

1. Template: python script.py --param_one ${group.param_one}
2. Dict: python script.py ${group}

But how do I reference a custom params file?

  params:
    - config/my_params.json:

Answer 1

You can use the top-level vars of dvc.yaml:

Given config/my_params.json:

{"group": {"foo": 1, "bar": 2}}

Your dvc.yaml would look like:

vars:
  - config/my_params.json

stages:
  echo-group:
    cmd: echo ${group}

Resulting in:

$ dvc repro
Running stage 'echo-group':                                                  
> echo --foo 1 --bar 2
--foo 1 --bar 2
Generating lock file 'dvc.lock'                                       
Updating lock file 'dvc.lock'