I don't think submodules are automatically imported, unless there are import statements in __init__.py.
On Sun, Sep 10, 2017 at 8:08 PM, INADA Naoki <songofaca...@gmail.com> wrote: > It looks simple and easy to understand. > > To achieve lazy import without breaking backward compatibility, > I want to add one more rule: When package defines both of __getattr__ and > __all__, automatic import of submodules are disabled (sorry, I don't have > pointer to specification about this behavior). > > For example, some modules depends on email.parser or email.feedparser. > But since email/__init__.py uses __all__, all submodules > are imported eagerly. > > See https://github.com/python/cpython/blob/master/Lib/email/ > __init__.py#L7-L25 > > Changing __all__ will break backward compatibility. > With __getattr__, this can be lazy import: > > import importlib > > def __getattr__(name): > if name in __all__: > return importlib.import_module("." + name, __name__) > raise AttributeError(f"module {__name__!r} has no attribute {name!r}") > > > Regards, > > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ > > -- --Guido van Rossum (python.org/~guido)
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