hello_world.py

# Python 3.6
# https://reddit.com/r/ProgrammerHumor/comments/cv6da5/_/ey28dm9/?context=1
    (lambda _, __, ___, ____, _____, ______, _______, ________:
        getattr(
            __import__(True.__class__.__name__[_] + [].__class__.__name__[__]),
            ().__class__.__eq__.__class__.__name__[:__] +
            ().__iter__().__class__.__name__[_:][_____:________]
        )(
            _, (lambda _, __, ___: _(_, __, ___))(
                lambda _, __, ___:
                    bytes([___ % __]) + _(_, __, ___ // __) if ___ else
                    (lambda: _).__code__.co_lnotab,
                _ << ________,
                (((_____ << ____) + _) << ((___ << _____) - ___)) + (((((___ << __)
                - _) << ___) + _) << ((_____ << ____) + (_ << _))) + (((_______ <<
                __) - _) << (((((_ << ___) + _)) << ___) + (_ << _))) + (((_______
                << ___) + _) << ((_ << ______) + _)) + (((_______ << ____) - _) <<
                ((_______ << ___))) + (((_ << ____) - _) << ((((___ << __) + _) <<
                __) - _)) - (_______ << ((((___ << __) - _) << __) + _)) + (_______
                << (((((_ << ___) + _)) << __))) - ((((((_ << ___) + _)) << __) +
                _) << ((((___ << __) + _) << _))) + (((_______ << __) - _) <<
                (((((_ << ___) + _)) << _))) + (((___ << ___) + _) << ((_____ <<
                _))) + (_____ << ______) + (_ << ___)
            )
        )
    )(
        *(lambda _, __, ___: _(_, __, ___))(
            (lambda _, __, ___:
                [__(___[(lambda: _).__code__.co_nlocals])] +
                _(_, __, ___[(lambda _: _).__code__.co_nlocals:]) if ___ else []
            ),
            lambda _: _.__code__.co_argcount,
            (
                lambda _: _,
                lambda _, __: _,
                lambda _, __, ___: _,
                lambda _, __, ___, ____: _,
                lambda _, __, ___, ____, _____: _,
                lambda _, __, ___, ____, _____, ______: _,
                lambda _, __, ___, ____, _____, ______, _______: _,
                lambda _, __, ___, ____, _____, ______, _______, ________: _
            )
        )
    )