BUG: can't use builtin functions due to inspect.py

[NickCrews]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pytask.

• (optional) I have confirmed this bug exists on the main branch of pytask.

---

Code Sample, a copy-pastable example

from pathlib import Path
import time

import pytask

task_build_time = pytask.task(produces=Path("build_time.txt"))(time.asctime)

╭─────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ in exec_module:940                                                                               │
│ in _call_with_frames_removed:241                                                                 │
│                                                                                                  │
│ /Users/nc/code/scg/kobuk/kobuk/tasks2/task_bug.py:6 in <module>                                  │
│                                                                                                  │
│   3                                                                                              │
│   4 import pytask                                                                                │
│   5                                                                                              │
│ ❱ 6 task_build_time = pytask.task(produces=Path("build_time.txt"))(time.asctime)                    │
│   7                                                                                              │
│                                                                                                  │
│ /Users/nc/code/scg/kobuk/.venv/lib/python3.11/site-packages/_pytask/task_utils.py:97 in wrapper  │
│                                                                                                  │
│    94 │   │                                                                                      │
│    95 │   │   unwrapped = inspect.unwrap(func)                                                   │
│    96 │   │                                                                                      │
│ ❱  97 │   │   raw_path = inspect.getfile(unwrapped)                                              │
│    98 │   │   if "<string>" in raw_path:                                                         │
│    99 │   │   │   path = Path(unwrapped.__globals__["__file__"]).absolute().resolve()            │
│   100 │   │   else:                                                                              │
│                                                                                                  │
│ /Users/nc/.pyenv/versions/3.11.6/lib/python3.11/inspect.py:920 in getfile                        │
│                                                                                                  │
│    917 │   │   object = object.f_code                                                            │
│    918 │   if iscode(object):                                                                    │
│    919 │   │   return object.co_filename                                                         │
│ ❱  920 │   raise TypeError('module, class, method, function, traceback, frame, or '              │
│    921 │   │   │   │   │   'code object was expected, got {}'.format(                            │
│    922 │   │   │   │   │   type(object).__name__))                                               │
│    923                                                                                           │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
TypeError: module, class, method, function, traceback, frame, or code object was expected, got builtin_function_or_method

Problem description

Expected Output

Any callable should work?

[tobiasraabe]

😄 We almost posted our PRs at the same time. Thanks for your PR!

I quickly checked how much effort supporting built-in functions would be. It would be hard since

• It would require some inspect.stack magic to figure out the module where the function is declared.
• You cannot attach arbitrary attributes to built-in functions like pytask_meta.

Thus, I decided to throw an error. The user can still wrap these functions in lambda or proper function definitions.

[NickCrews]

Wait this makes me wonder: does pytask.task(), always modify that function (adding pytask_meta etc)? If it were possible, I think it would be much better to never modify the input, and instead

1. create a little wrapper function that just calls the passed in func
2. add pytask_meta to the wrapper
3. register that wrapper as the actual task function
4. return the wrapper

This would reduce the number of side effects. Having my existing function getting modified during task creation hasn't been a problem for me yet, but I could see that being a whole class of nasty bugs.

This is all tangential to the builtin stuff that was the reason for this issue. I think it's fine to not support builtins for now, we could always re-allow them later. This proposed change would sidestep the issue 2 you mention above about adding attributes to builtins, but the inspect stuff is still a problem.