It was very easy to load plugin files in Python 2:

import imp
my_module = imp.load_source("what.ever", "foo.py")

Unfortunately, this became much more obscure in Python 3.3:

import importlib.machinery
loader = importlib.machinery.SourceFileLoader("what.ever", "foo.py")
my_module = loader.load_module("what.ever")

In Python 3.4 even this has been deprecated. There should be a way (preferable an easy-to-use one) to load a Python module by filename or by stream.

So it's not quite as bad as you think as SourceFileLoader.load_module() doesn't need an argument (I've opened http://bugs.python.org/issue21438 to fix the documentation). Admittedly it is a longer command than imp.load_source() to type, but there is no extra information required or a necessity that you break the command up into multiple lines.

Plus imp.load_source() is just plain bad. The reason the imp module is deprecated in Python 3.4 is because it does not expose the low-level details of import in a way that makes any sense since Python 2.3 (and yes, I meant to write 2.3 instead of 3.3; the problem has persisted _that_ long).

That being said, talks are just starting to consider undoing the documented deprecation of load_module() such that you can continue to use that as a substitute for imp.load_source()/imp.load_module().

I'm going to leave this bug open, hijack its title, and refocus this as to consider leaving importlib.abc.Loader.load_module() in importlib as the all-powerful fallback API which also simplifies transitioning from imp.

I'd rather see something like "load_from_spec()" added to importlib.util, a la issue #21235.

Python 3.5 lets you do:

  spec = importlib.util.spec_from_file_location('what.ever', 'foo.py')
  module = importlib.util.module_from_spec(spec)
  spec.loader.exec_module(module)

I am satisfied that case for loading from a file is easy enough to not warrant keeping load_module() around just for this use case.