On 28Nov2016 1419, Nathaniel Smith wrote:
I'd suggest that we additional specify that if we find a foo.missing.py, then the code is executed but -- unlike a regular module load -- it's not automatically inserted into sys.modules["foo"]. That seems like it could only create confusion. And it doesn't restrict functionality, because if someone really wants to implement some clever shenanigans, they can always modify sys.modules["foo"] by hand.
In before Brett says "you can do this with an import hook", because, well, we can do this with an import hook :) Given that, this wouldn't necessarily need to be an executable file. The finder could locate a "foo.missing" file and raise ModuleNotFoundError with the contents of the file as the message. No need to allow/require any Python code at all, and no risk of polluting sys.modules. Cheers, Steve