bpo-32856: Optimize the assignment idiom in comprehensions. #16814
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Now `for y in [expr]` in comprehensions is so fast as a simple assignment `y = expr`.
serhiy-storchaka
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Jan 8, 2020
Doc/whatsnew/3.9.rst
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| @@ -227,6 +227,17 @@ signals to a process using a file descriptor instead of a pid. (:issue:`38712`) | |||
| Optimizations | |||
| ============= | |||
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| * Optimized the idiom for assignment a temporary variable in comprehensions. | |||
| Now ``for y in [expr]`` in comprehensions is so fast as a simple assignment | |||
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"as fast as" (also in news file)
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Done. Thank you.
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LGTM |
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Now
for y in [expr]in comprehensions is so fast as a simple assignmenty = expr.Unlike to the
:=operator this idiom does not leak a variable to the outer scope.https://bugs.python.org/issue32856