RFC-434 we deprecated PropertySet.get() and replaced it with getScalar and getArray. Whilst this seems safer for many users, it means that a PropertySet can't ever behave like a Python dict. This is a real annoyance with astro_metadata_translator since that accepts any dict-like headers (including those from Astropy) and I have to have special workarounds all over it to convert PropertyList to dict.
Can I please add PropertySet.__getitem__ which behaves like get() and allows me to say ps["KEY"]? (there is a __setitem__ already for assignment using normal dict syntax). The toDict and toOrderedDict methods already use the Pythonic approach of returning a list or scalar depending on the contents of the PropertyList.
Ideally I'd like to add back a get() that looks like a dict get and allows defaulting, but I imagine that is a harder sell.
This __getitem__ proposal is adding to the API and not changing any existing API.