Opened 9 years ago
Last modified 5 years ago
#15648 new defect
lazy import attributes of a class are not substituted back after the import
Reported by: | nthiery | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | misc | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
sage: class A: ....: Associative = LazyImport('sage.categories.magmas', 'Magmas') ....: sage: A.Associative <class 'sage.categories.magmas.Magmas'> sage: type(A.__dict__["Associative"]) <type 'sage.misc.lazy_import.LazyImport'>
Change History (15)
comment:1 Changed 9 years ago by
comment:2 Changed 9 years ago by
Strange. Shouldn't LazyImport
already act as a class attribute? After all, I see the following code:
if owner is None: if self._namespace and self._namespace[alias] is self: self._namespace[alias] = self._object else: from inspect import getmro for cls in getmro(owner): if cls.__dict__.get(alias, None) is self: setattr(cls, alias, self._object) break
This should actually do the trick.
comment:3 Changed 9 years ago by
In the example of the ticket description, I suppose you simply need to proved as_name="Associative"
, and then it should work. Can't test it right now, though.
comment:4 follow-up: ↓ 5 Changed 9 years ago by
The only (mild) problems I see:
- Why is the
_get_object
, if it does what ostensibly is the job of__get__
? - Why is the imported object put into the dict of a class, but not into the dict of an instance?
_get_object
can't do it, since it doesn't know the instance.
Hence, I am all for removing _get_object
.
comment:5 in reply to: ↑ 4 Changed 9 years ago by
- Status changed from new to needs_info
- Work issues set to Do we need a lazy import to act as lazy instance attribute?
sage: from sage.misc.lazy_import import LazyImport sage: class A: ....: Associative = LazyImport('sage.categories.magmas', 'Magmas', 'Associative') ....: sage: A.Associative <class 'sage.categories.magmas.Magmas'> sage: A.__dict__['Associative'] <class 'sage.categories.magmas.Magmas'>
Hence, unless you agree that we should change the lazy import statement so that it additionally acts as a lazy instance attribute, then this ticket is invalid.
comment:6 Changed 9 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:7 Changed 8 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:8 Changed 8 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:9 Changed 5 years ago by
- Dependencies set to #22752
- Milestone changed from sage-6.4 to sage-8.0
- Type changed from PLEASE CHANGE to defect
- Work issues Do we need a lazy import to act as lazy instance attribute? deleted
comment:10 Changed 5 years ago by
- Branch set to u/jdemeyer/ticket/15648
comment:11 Changed 5 years ago by
- Commit set to d5f23484bd61b280dcf5b716f58fe31a6847e18d
- Status changed from needs_info to needs_review
comment:12 Changed 5 years ago by
- Commit changed from d5f23484bd61b280dcf5b716f58fe31a6847e18d to 796a45277a23c14ea86126f5e08349f2c25c34d2
comment:13 Changed 5 years ago by
- Milestone changed from sage-8.0 to sage-duplicate/invalid/wontfix
- Resolution set to wontfix
- Status changed from needs_review to closed
comment:14 Changed 5 years ago by
- Branch u/jdemeyer/ticket/15648 deleted
- Commit 796a45277a23c14ea86126f5e08349f2c25c34d2 deleted
- Resolution wontfix deleted
- Status changed from closed to new
comment:15 Changed 5 years ago by
- Dependencies #22752 deleted
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See my comment at #10963. We could simply create a lazy class attribute with an import statement inside. Proof of concept:
Alternatively, since
LazyImport
has some__get__
: We could make the lazy import behave as a class attribute, if it is used as attribute of a class (__get__
knows whether it is used as attribute of a class.