Tab completion / dir broken on concurrent.futures

[henryiii]

Bug report

Bug description:

I just noticed that in 3.14rc1, tab completion is broken on concurrent.futures. Trying dir, I got:

>>> import concurrent.futures
>>> dir(concurrent.futures)
Traceback (most recent call last):
  File "<python-input-2>", line 1, in <module>
    dir(concurrent.futures)
    ~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/henryschreiner/.local/share/uv/python/cpython-3.14.0rc1+freethreaded-macos-x86_64-none/lib/python3.14t/concurrent/futures/__init__.py", line 47, in __dir__
    return __all__ + ('__author__', '__doc__')
           ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
TypeError: can only concatenate list (not "tuple") to list

There's a typo in the __dir__ function; it is trying to concatenate a list and a tuple.

Bug introduced in #136381. Fix in #137214.

CPython versions tested on:

3.14

Operating systems tested on:

No response

Linked PRs

• gh-137282: Fix tab completion and dir() on concurrent.futures #137214
• [3.14] gh-137282: Fix TypeError in tab completion and dir() of concurrent.futures (GH-137214) #137284

[ZeroIntensity]

This is a 3.14 regression so I've marked this as a blocker.