Subclassing threading Lock/RLock: better Exception messages
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 45/100
- Issue type
- Bug
- Clarity
- Mostly clear
- Activity status
- Stale
- Tech stack
- python
- Domain
- operating-systems
Research direction
Start with the minimal Python reproduction in the issue and inspect the threading documentation entry for Lock and RLock. Determine how unsupported subclassing is currently exposed, then make the behavior clearer through a friendlier error message and documentation stating the subclassing limitation. Re-run both subclass definitions to verify the resulting messages.
Written by the indexing model from the issue text.
Description
Bug report
Please see the below minimal repro:
from threading import Lock, RLock
class SubclassLock(Lock):
pass
class SubclassRLock(RLock):
pass
The subclass of Lock emits:
Traceback (most recent call last):
File "/path/to/file.py", line 3, in <module>
class SubclassLock(Lock):
TypeError: cannot create 'builtin_function_or_method' instances
The subclass of RLock emits:
Traceback (most recent call last):
File "/path/to/file.py", line 6, in <module>
class SubclassRLock(RLock):
TypeError: function() argument 'code' must be code, not str
Both of these messages are relatively cryptic. I think if Python doesn't support subclassing Lock/RLock, it should be documented in threading, and this error message should be more friendly/clear.
Your environment
- CPython versions tested on: 3.10.3
- Operating system and architecture: macOS Big Sur 11.5.1
- Dominant language
- Python
- Stars
- 77.2k
- Forks
- 36k
- Avg merge
- 1d 9h
- Merged PRs (30d)
- 558
Contributor guide
First steps
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