load triggered in IPython upon any error raised?

[dschult]

While trying to find a way to make lazy_loader.load work for subpackages (see #55), I discovered that IPython triggers a load of a lazily loaded package upon any exception being raised. A regular Python session does not.

Example:

import lazy_loader
mpl = lazy_loader.load("matplotlib")
print(type(mpl))  # result is <class 'importlib.util._LazyModule'>
raise Exception()
print(type(mpl))  # result is <class 'module'>

The same code run in a python session does not trigger the loading of the lazy module.

I checked that nothing is calling the module's __getattr__ during that process. But something in IPython seems to be triggering the loading of lazily loaded modules.

Is this another reason to remove load from the package?

[stefanv]

@dschult I don't know; is this behavior a problem?

[stefanv]

Python does all sorts of introspection into objects, so it's not surprising that, somewhere along the line, it triggers importing. I will close for now, unless you think we should fix this in lazy_loader itself.