sonntagsgesicht/tslist ? reverse-engineered prompt

Build me a small Python package called tslist that acts like a normal list, but lets me filter items by value using slice style lookups. I want to be able to create a TSList from numbers or other comparable objects, then do things like grab everything between two values, get exact matches, and use step values too. If items can be converted, the filtering should use those conversions so it works nicely with custom types.

Please include a TS helper for timestamp and datetime style conversion, since the package is meant to make time based lists easy to work with. Add a few simple examples and tests that show the main behavior, especially with floats and custom date or timedelta like objects. Keep the API small and friendly, and make sure it feels like a lightweight library I could install and import right away. If anything is unclear, look up the current docs online if you need to.