A way to simplify complicated Cookiecutters is the Options Pattern. If I step away from Cookiecutter for any duration, I forget about it. Thanks to Mark Patricio for the reminder!

Complex example we'll simplify:

Take a look at the arguments code:

// cookiecutter.json
{
  "project_name": "thing",
  "volume": ["low", "medium", "high"]
}

And the template code (line breaks added so it fits on computer/tablet/mobile screens):

# thing/config.py
# Volume: {% if cookiecutter.volume == "low" %}low
  {% elif cookiecutter.volume == "medium" %}medium
  {% elif cookiecutter.volume == "high" %}high{% endif %}
VOLUME_SETTING = {% if cookiecutter.volume == "low" %}5
  {% elif cookiecutter.volume == "medium" %}10
  {% elif cookiecutter.volume == "high" %}15{% endif %}

Simplified example:

First the arguments code, which now contains a __volume_options field.

// cookiecutter.json
{
  "project_name": "thing",
  "volume": ["low", "medium", "high"]
  "__volume_options": {
    "low": 5,
    "medium": 10,
    "high": 15
  }
}

By prefixing the __volume_options with double underscores, the field is now a private variable. This means it isn't displayed to the user during the arguments stage. Rather, it is just passed into the context of the template.

This __volume_options field is also a dict variable. It is a key/value type of object. This is important, as the Jinja renderer of Cookiecutter allows us to fetch the value of the pair by calling the key.

Having __volume_options built around these two features allows us to simplify the template to the point where we don't need to add linebreaks to make it legible:

# thing/config.py
# Volume: {{ cookiecutter.volume }}
VOLUME_SETTING = {{ cookiecutter.__volume_options[cookiecutter.volume] }}  

Simplified result for easy reference

// cookiecutter.json
{
  "project_name": "thing",
  "volume": ["low", "medium", "high"]
  "__volume_options": {
    "low": 5,
    "medium": 10,
    "high": 15
  }
}

# thing/config.py
# Volume: {{ cookiecutter.volume }}
VOLUME_SETTING = {{ cookiecutter.__volume_options[cookiecutter.volume] }}  

Extra benefits to this approach

This puts more of the data into cookiecutter.json rather than the templates. Discovery of values is easier, smoothing the path for maintenance or new features.