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authorJörn Heissler <joernheissler@users.noreply.github.com>2019-06-22 14:40:55 (GMT)
committerMiss Islington (bot) <31488909+miss-islington@users.noreply.github.com>2019-06-22 14:40:55 (GMT)
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parentbb110cc2ed81447fb48805f31146cf31323a8fc3 (diff)
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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
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@@ -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: