argparse missing from libpython3.7-stdlib ?

[Frank Miles <pedicularis@mail.com>]

It seems that the new testing/buster python3.7 lacks 'argparse'.
Simply trying to import this causes an error, probably due to
only a python2.7 version on my system.

I didn't see any indication of a missing library, though there
is apparently some kind of transition going on. Is my system
missing some other python library?

Thanks for any insights!
-F