> What exactly makes Python 3.6 a "decent step up" from 2.7?

The language and the standard lib improved a lot. There are so many improvements, it would be impossible to list them all after so many years of progress...

Just to name a few of the bigger improvements, that I have discovered recently:

* The typing module lets you add type annotations to your code and write code like this:

    class User(NamedTuple):
        id: int
        name: str
        age: int

    def remove_user(u: User) -> None:
        # ...

    fred = User(123, 'fred', 42)
    # ...
    remove_user(fred)

* F-strigs are awesome:

   file_path = f'{base_dir}/{user_name}/{latest_dir}'

* I think asyncio and the async/await syntax are great.

* The refactoring of the subprocess module:

    subprocess.run(my_cmd)

* The documentation of the standard lib improved a lot, if you ask me.

This is just off the top of my head...

But really, it's the overall improvement of the language and the standard lib that make the difference, not just the big features.