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| author | Serhiy Storchaka <storchaka@gmail.com> | 2021-06-08 23:31:10 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-06-08 23:31:10 (GMT) |
| commit | 2ea6d890281c415e0a2f00e63526e592da8ce3d9 (patch) | |
| tree | 0aff5648b72d3c7b4557408f8adfce932c59a237 /Doc/whatsnew/3.10.rst | |
| parent | 3e1c7167d86a2a928cdcb659094aa10bb5550c4c (diff) | |
| download | cpython-2ea6d890281c415e0a2f00e63526e592da8ce3d9.zip cpython-2ea6d890281c415e0a2f00e63526e592da8ce3d9.tar.gz cpython-2ea6d890281c415e0a2f00e63526e592da8ce3d9.tar.bz2 | |
bpo-43833: Emit warnings for numeric literals followed by keyword (GH-25466)
Emit a deprecation warning if the numeric literal is immediately followed by
one of keywords: and, else, for, if, in, is, or. Raise a syntax error with
more informative message if it is immediately followed by other keyword or
identifier.
Automerge-Triggered-By: GH:pablogsal
Diffstat (limited to 'Doc/whatsnew/3.10.rst')
| -rw-r--r-- | Doc/whatsnew/3.10.rst | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst index 74e6b03..df9806a 100644 --- a/Doc/whatsnew/3.10.rst +++ b/Doc/whatsnew/3.10.rst @@ -1444,6 +1444,17 @@ Optimizations Deprecated ========== +* Currently Python accepts numeric literals immediately followed by keywords, + for example ``0in x``, ``1or x``, ``0if 1else 2``. It allows confusing + and ambigious expressions like ``[0x1for x in y]`` (which can be + interpreted as ``[0x1 for x in y]`` or ``[0x1f or x in y]``). Starting in + this release, a deprecation warning is raised if the numeric literal is + immediately followed by one of keywords :keyword:`and`, :keyword:`else`, + :keyword:`for`, :keyword:`if`, :keyword:`in`, :keyword:`is` and :keyword:`or`. + If future releases it will be changed to syntax warning, and finally to + syntax error. + (Contributed by Serhiy Storchaka in :issue:`43833`). + * Starting in this release, there will be a concerted effort to begin cleaning up old import semantics that were kept for Python 2.7 compatibility. Specifically, @@ -1670,6 +1681,18 @@ This section lists previously described changes and other bugfixes that may require changes to your code. +Changes in the Python syntax +---------------------------- + +* Deprecation warning is now emitted when compiling previously valid syntax + if the numeric literal is immediately followed by a keyword (like in ``0in x``). + If future releases it will be changed to syntax warning, and finally to a + syntax error. To get rid of the warning and make the code compatible with + future releases just add a space between the numeric literal and the + following keyword. + (Contributed by Serhiy Storchaka in :issue:`43833`). + + Changes in the Python API ------------------------- |