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code.co_positions behaviour does not match documentation #100117
Description
The documentation of co_positions() says:
The iterator returns tuples containing the (start_line, end_line, start_column, end_column). The i-th tuple corresponds to the position of the source code that compiled to the i-th instruction.
I think this is incorrect, because the iterator returns tuples for cache entries as well:
>>> def f():
... a.b = 1
...
>>> import dis
>>> dis.dis(f)
1 0 RESUME 0
2 2 LOAD_CONST 1 (1)
4 LOAD_GLOBAL 0 (a)
16 STORE_ATTR 1 (b)
26 LOAD_CONST 0 (None)
28 RETURN_VALUE
>>> len(list(f.__code__.co_positions()))
15
>>> from pprint import pprint as pp
>>> pp(list(f.__code__.co_positions()))
[(1, 1, 0, 0),
(2, 2, 8, 9),
(2, 2, 2, 3),
(2, 2, 2, 3),
(2, 2, 2, 3),
(2, 2, 2, 3),
(2, 2, 2, 3),
(2, 2, 2, 3),
(2, 2, 2, 5),
(2, 2, 2, 5),
(2, 2, 2, 5),
(2, 2, 2, 5),
(2, 2, 2, 5),
(2, 2, 2, 5),
(2, 2, 2, 5)]
>>>
Linked PRs
- GH-100117: Make
co_linesmore efficient #100447 - gh-100117: Fix inaccuracy in documentation of the CodeObject's co_positions field. #119364
- [3.13] gh-100117: Fix inaccuracy in documentation of the CodeObject's co_positions field. (GH-119364) #119869
- [3.12] gh-100117: Fix inaccuracy in documentation of the CodeObject's co_positions field. (GH-119364) #119870
- [3.11] gh-100117: Fix inaccuracy in documentation of the CodeObject's co_positions field. (GH-119364) #119871
Activity
iritkatriel commentedon Dec 8, 2022
CC @markshannon @brandtbucher .
[-]error documentation of code.co_positions[/-][+]error in documentation of code.co_positions[/+][-]error in documentation of code.co_positions[/-][+]code.co_positions behaviour does not match documentation[/+]brandtbucher commentedon Dec 21, 2022
I think this is probably just a place where the docs could be improved.
Are you suggesting replacing "instruction" with "code unit"? Or adding a note that inline
CACHE"instructions" are included? I'd be fine with either.iritkatriel commentedon Dec 22, 2022
We discussed this at the meeting and I think the view was that the implementation needs to change. @markshannon ?
markshannon commentedon Dec 22, 2022
I don't think we can change the current behavior of emitting one tuple per code unit . The docs should reflect that behaviour.
I think it is
co_lines()that we should modify. We can merge successive tuples with the same line number, now that #99556 is merged.GH-100117: Make `co_lines` more efficient (GH-100447)
iritkatriel commentedon Dec 11, 2023
This shouldn't have been closed, the doc is still incorrect.
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
gh-100117: Fix inaccuracy in documentation of the CodeObject's co_pos…
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
[3.12] gh-100117: Fix inaccuracy in documentation of the CodeObject's…
[3.13] gh-100117: Fix inaccuracy in documentation of the CodeObject's…
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
pythongh-100117: Fix inaccuracy in documentation of the CodeObject's …
[3.11] gh-100117: Fix inaccuracy in documentation of the CodeObject's…