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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2019-06-22 22:34:03 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-06-22 22:34:03 (GMT) |
| commit | 874ff65e0a70ff4fd1a67e85cd61d76adfcc219d (patch) | |
| tree | 56f0a7d275a2283001ce6ca87168d000c995438c /Doc/reference | |
| parent | fa23bd286fb7719bd7601da0b713457589f5536f (diff) | |
| download | cpython-874ff65e0a70ff4fd1a67e85cd61d76adfcc219d.zip cpython-874ff65e0a70ff4fd1a67e85cd61d76adfcc219d.tar.gz cpython-874ff65e0a70ff4fd1a67e85cd61d76adfcc219d.tar.bz2 | |
bpo-35224: Reverse evaluation order of key: value in dict comprehensions (GH-14139)
… as proposed in PEP 572; key is now evaluated before value.
https://bugs.python.org/issue35224
(cherry picked from commit c8a35417db8853a253517a3e5190e174075c6384)
Co-authored-by: Jörn Heissler <joernheissler@users.noreply.github.com>
Diffstat (limited to 'Doc/reference')
| -rw-r--r-- | Doc/reference/expressions.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index 8b71106..432327a 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -337,6 +337,12 @@ all mutable objects.) Clashes between duplicate keys are not detected; the last datum (textually rightmost in the display) stored for a given key value prevails. +.. versionchanged:: 3.8 + Prior to Python 3.8, in dict comprehensions, the evaluation order of key + and value was not well-defined. In CPython, the value was evaluated before + the key. Starting with 3.8, the key is evaluated before the value, as + proposed by :pep:`572`. + .. _genexpr: |