IDAPython: How to pass arguments and retrieve them from my Python script or plugin?

Whole-channel inclusion: AllThingsIDA - (now @Binary-Wizards) is an honest teaching channel (title sample + 3 transcripts read: All sampled items lack transcripts, so the verdict relies on the title-sample assessment indicating the channel is a genuine technical tutorial channel on IDA Pro and reverse engineering.); this title passed a strict title check (sonnet) after a labelling pass.