[Python-ideas] Provide a way to import module without exec body

[Neil Schemenauer]

I have been working on reducing Python statup time.  It would be
nice if there was some way to load a module into memory without exec
of its body code.  I'm sure other people have wished for this.

Perhaps there could be a new special function, similar to __import__
for this purpose.  E.g.  __load_module__().  To actually execute the
module, I had the idea to make module objects callable, i.e. tp_call
for PyModule_Type.  That's a little too cute though and will cause
confusion.  Maybe instead, add a function attribute to modules, e.g.
mod.__exec__().

I have a little experimental code, just a small step:

https://github.com/nascheme/cpython/tree/import_defer_exec

We need importlib to give us the module object and the bytecode
without doing the exec().  My hackish solution is to set properties
on __spec__ and then have PyImport_ImportModuleLevelObject() do the
exec().