dis.cmp_op doc is inaccurate in Python 3.12.2 and 3.13.0a5
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Description
Bug report
Bug description:
From https://docs.python.org/3.12/library/dis.html#opcode-COMPARE_OP,
dis.cmp_op should be able lookup the comparison operation string from the opcode's argument.
However, in Python 3.12.2 and 3.13.0a5, this fails with "IndexError: tuple index out of range"
import dis
def my_fun(a, b):
return a <= b
for instruction in dis.get_instructions(my_fun):
if instruction.opname == 'COMPARE_OP':
print(dis.cmp_op[instruction.arg])
In Python 3.11.8, it prints "<=" as expected.
dis.dis output of my_fun in Python 3.12.2:
1 0 RESUME 0
2 2 LOAD_FAST 0 (a)
4 LOAD_FAST 1 (b)
6 COMPARE_OP 26 (<=)
10 RETURN_VALUE
dis.cmp_op in Python 3.12.2:
('<', '<=', '==', '!=', '>', '>=')
Workaround: use instruction.argrepr.
CPython versions tested on:
3.12, 3.13
Operating systems tested on:
Linux
Linked PRs
- gh-117272
- gh-117274
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 with the dis.cmp_op documentation and the reported dis.get_instructions() example, then compare the Python 3.12 and 3.13 behavior with Python 3.11. Review linked PRs gh-117272 and gh-117274 for the current direction; done means the documentation accurately explains the comparison-operation lookup and the available workaround.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100