How would you write a decorator that takes its own arguments?

You add a third layer. The outer function takes the decorator arguments and returns the actual decorator, which takes the function and returns a wrapper that calls it. Apply functools.wraps to the wrapper so the name, docstring, and signature metadata survive. For example, a retry decorator takes the attempt count at the outer layer and the wrapper implements the loop.

Three layers, and I say them out loud in order so I do not lose track. The outermost function takes the configuration, say the number of retries. It returns the decorator, which takes the target function. That returns the wrapper, which takes star args and star star kwargs, does the work around the call, and returns the result. I always put functools.wraps on the wrapper, otherwise the decorated function reports itself as wrapper everywhere, and Flask or Celery will happily register two routes under the same name and fail in a confusing way. The one I have written most often is a retry with exponential backoff for flaky upstream calls: three attempts, sleeping a doubling interval, re raising on the last one. A useful refinement is accepting the function directly as well, so it works with and without parentheses, though honestly I usually just require the parentheses because the branching logic costs more clarity than it saves.