Fix __ge__ and __gt__ comparison methods #22
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Quoting the Python documentation for sets: "The subset and equality comparisons do not generalize to a total ordering function. For example, any two nonempty disjoint sets are not equal and are not subsets of each other, so all of the following return False: a<b, a==b, or a>b." It is therefore not possible to define __ge__ as the inverse of __lt__ (and similarly __gt__ as the inverse of __le__), since this will give false positive results. Fix by implementing __ge__ and __gt__ using equivalent logic to that used in __le__ and __lt__. Signed-off-by: Michael Brown <[email protected]>
Author
|
Do you have any queries or requested changes? Would it help if I opened an issue to report the original bug that is fixed by this patch? Thanks, Michael |
|
@simonpercivall Any thoughts on this PR? |
|
Until this issue is resolved here, may want to check out #38 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Quoting the Python documentation for sets:
"The subset and equality comparisons do not generalize to a total
ordering function. For example, any two nonempty disjoint sets are
not equal and are not subsets of each other, so all of the
following return False: a<b, a==b, or a>b."
It is therefore not possible to define ge as the inverse of lt
(and similarly gt as the inverse of le), since this will give
false positive results.
Fix by implementing ge and gt using equivalent logic to that
used in le and lt.
Signed-off-by: Michael Brown [email protected]