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| author | Serhiy Storchaka <storchaka@gmail.com> | 2019-01-18 05:47:48 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-01-18 05:47:48 (GMT) |
| commit | 3bcbedc9f1471d957a30a90f9d1251516b422416 (patch) | |
| tree | 8011052f704ebd4db1a1b77d04f9dc831bf35d2e /Doc | |
| parent | e55cf024cae203f63b4f78f1b21c1375fe424441 (diff) | |
| download | cpython-3bcbedc9f1471d957a30a90f9d1251516b422416.zip cpython-3bcbedc9f1471d957a30a90f9d1251516b422416.tar.gz cpython-3bcbedc9f1471d957a30a90f9d1251516b422416.tar.bz2 | |
bpo-34850: Emit a warning for "is" and "is not" with a literal. (GH-9642)
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/whatsnew/3.8.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst index bf8d8f1..0360be6 100644 --- a/Doc/whatsnew/3.8.rst +++ b/Doc/whatsnew/3.8.rst @@ -442,6 +442,13 @@ Changes in Python behavior in the leftmost :keyword:`!for` clause). (Contributed by Serhiy Storchaka in :issue:`10544`.) +* The compiler now produces a :exc:`SyntaxWarning` when identity checks + (``is`` and ``is not``) are used with certain types of literals + (e.g. strings, ints). These can often work by accident in CPython, + but are not guaranteed by the language spec. The warning advises users + to use equality tests (``==`` and ``!=``) instead. + (Contributed by Serhiy Storchaka in :issue:`34850`.) + Changes in the Python API ------------------------- |