Just wanted to note another possibility (most likely to be added to the "rejected solutions" section).

Add a prefix "!" operator, which will work similarly to the iterator-unpacking operator "*", but for None.

The expression "[!x]" is equivalent to the expression "[] if x is None else [x]".

This can be combined with the "or" operator, now working as expected since it's about lists, and a simple "first" or "single" library function.

Example:

optdict = dict(encoding=single([!encoding] or sys.getdefaultencoding()), css=options.css)

It is more verbose than the proposed "??" operator (which I personally like), but maybe it's less line noise.

One can use it with simple parens and get a tuple, "(!x) or y". note that "(!x or y)" is a syntax error in this case.

Another, related idea: instead of "??" use a double-token operator "! or":

value = ham! or spam! or eggs

optdict = dict(encoding=encoding! or sys.getdefaultencoding(), css=options.css)

Elazar