Once you have imported foo module in which you have the bar class with
import importlib
foo = importlib.import_module('path/to/foo')
How do you do to simply call bar.run() instead of foo.bar.run()?
I guess you can to this bar = foo.bar
but I want to do it for all objects in foo, and I can't do it each by each, it will take too much time.
You would likely need to enumerate the exported objects from the foo module, and assign them to global variables. In the normal mechanism for importing modules, * will either match the names listed in the __all__ variable or will grab all names that don't start with an underscore (_).
names = getattr(foo, '__all__', [])
if not names:
names = [n for n in foo.__dict__.keys() if n[:1] != '_']
for name in names:
globals()[name] = getattr(foo, name)