Thank you all, I learned from you that it's possible to have a callable module. Although `sys.modules[__name__] = wat` looks like a black magic and I'm a bit afraid of locking out to other importable things in this package, I think I'll go for it.
import sys
def wat(): print("wat")
def bar(): print("bar")
wat.wat = wat
wat.bar = bar
sys.modules[__name__] = wat
>>> import wat
>>> wat()
wat
>>> from wat import bar
>>> bar()
bar