Traceback Shows Too Much Info For Class Definition Exception
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Nobody has claimed this yet.
3.14
interpreter-core
stdlib
type-bug
- Dominant language
- Python
- Stars
- 77.2k
- Forks
- 35.9k
- PR merge metrics
- PR metrics pending
Description
Bug report
Bug description:
Given the following:
class Meta(type):
def __prepare__(cls, *args, **kwargs):
raise Exception
class Spam(metaclass=Meta):
a = 1
b = 2
c = 3
d = 4
e = 5
f = 6
I get:
Traceback (most recent call last):
File "<python-input-10>", line 1, in <module>
class Spam(metaclass=Meta):
...<5 lines>...
f = 6
File "<python-input-9>", line 3, in __prepare__
raise Exception
I would expect this to only show the compound statement's "header":
Traceback (most recent call last):
File "<python-input-10>", line 1, in <module>
class Spam(metaclass=Meta):
File "<python-input-9>", line 3, in __prepare__
raise Exception
CC @iritkatriel
CPython versions tested on:
CPython main branch
Operating systems tested on:
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the traceback on the CPython main branch with the class and metaclass example in the issue. Trace how the interpreter formats the class definition's source span and look for existing traceback tests covering compound statements. Done means the traceback shows only the class header before the prepare exception.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100