Nested substitutions

[JeeCee1]

Describe the problem you have/What new integration you would like

Maybe there is already another way to achieve my goal, I just haven't found one. I have created packages for modules (eg. temperature sensor, pulse counter). For some projects I am using multiple/duplicate sensors, so I have duplicated the packages (e.g. dht22_1.yaml, dht22_2.yaml etc.). I am using substitions for the names, and in the "main" file I am defining these names:

substitutions:
  `dht22_1_name: Elecmeters`. 

My request would be to be able to use this:

substitutions:
  name_lower: elecmeters
  dht22_1_name: ${name_lower}

I know I can directly use ${name_lower} in the referenced package, but in my situations that is not convenient. It would suffice to be able to use #DEFINE directives directly in the .yaml file, but I guess that conflicts with # being used for comments. Is it even possible to use C code directly in the yaml file?

Please describe your use case for this integration and alternatives you've tried:

This would help to mainatain a very clean and lean main project file. PS: If anyone knows of a way to avoid having to duplicate the package files that would be great!

Additional context

Thanks for any help!

[taintedkernel]

I have recently stated using packages in my code and realizing I would like the same feature. It seems quite useful if could create a standard package for a sensor, encapsulating the config and reusing it across multiple instances of the same node. I have some nodes with multiple instances of the same sensor (ATC MiThermometer), and similar to @JeeCee1 I discovered I cannot leverage packages here.

For a bit more clarification, I would like to be able to do something like the following:

# esphome/common/atc_mithermometer.yaml
sensor:
  - platform: atc_mithermometer
    mac_address: ${sensor_mac_address}
    temperature:
      name: "${sensor_name} Temperature"
    humidity:
      name: "${sensor_name} Humidity"
      accuracy_decimals: 1
      filters:
etc...

# node config esp32-node-1.yaml
substitutions:
  atc1:
    sensor_name: Downstairs
    sensor_mac_address: xx:xx:xx:xx:xx:xx
  atc2:
    sensor_name: Garage
    sensor_mac_address: xx:xx:xx:xx:xx:xx

packages:
  atc_mithermometer: !include common/atc_mithermometer.yaml

[JeeCee1]

ping

[joshuaspence]

I've also been wanting this, although I imagined it working a different way, similar to the remote package syntax:

packages:
  foo:
    path: './foo.yaml`
    substitutions:
      bar: 'baz'

[joshuaspence]

Looks like my suggestion was also made in https://github.com/esphome/feature-requests/issues/805#issuecomment-659669832

[nagyrobi]

See https://github.com/esphome/esphome/pull/3612