I'm looking at this because in modern Python it causes sys.meta_path finders to be called with mpf.find_spec('somepkg.module.', ...), (note the trailing fullstop). Which I'm fairly certain is wrong.
import(..., fromlist=['']) isn't unique to Mitogen. It's also in imagepy, webpy, cherrypy, and others https://grep.app/search?q=. Most examples use the returned value. I think it's meant as a way to get the leaf module, rather than the top-level package, e.g.
>>> import('xml.dom.minidom')
<module 'xml' from '.../xml/init.py'>
>>> import('xml.dom.minidom', fromlist=[''])
<module 'xml.dom.minidom' from '.../xml/dom/minidom.py'>
import(..., fromlist['']) is handled by code that swallows the exception. A comment notes "Backwards-compatibility dictates we ignore failed imports triggered by fromlist for modules that don't exist." https://github.com/python/cpython/blob/v3.12.2/Lib/importlib/_bootstrap.py#L1414-L1422 So I think it's a trick that became widespread in early Python (pre 2.x?), enough to be a grudgingly accepted unofficial API. I should specifically handle it as a corner case in Mitogen's find_spec(). #Python#Mitogen
@alex That's what I'm thinking too. I haven't seen "modern" code like that, The closest code I can think of was from the 2.x era.
The documentation says fromlist "gives the names of objects or submodules that should be imported from the module given by name," but I think you already figured that part out.
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