+1 to everything in [amon's answer][1]. I'd like to add this:

You'll regret using Python code as your configuration language the first time you want to import the same configuration from within code written in a different language. For example if code that's part of your project and it written in C++ or Ruby or something else needs to pull in the configuration, you'll need to link in the Python interpreter as a library or parse the configuration in a Python coprocess, both of which are awkward, difficult, or high-overhead.

All of the code that imports this configuration today may be written in Python, and you may think this will be true tomorrow as well, but do you know for sure?

You said you would use logic (anything other that static data structures) in your configuration sparingly if at all, which is good, but if there's any bit of that at all, you'll find it difficult in the future to undo it so you can move back to a declarative configuration file.

  [1]: https://softwareengineering.stackexchange.com/questions/351126/how-bad-of-an-idea-is-it-to-use-python-files-as-configuration-files/351128#351128