[Python-checkins] cpython (3.5): whatsnew/3.5: Mention PEP 448
yury.selivanov
python-checkins at python.org
Tue Aug 4 18:42:51 CEST 2015
https://hg.python.org/cpython/rev/731b8caaa855
changeset: 97238:731b8caaa855
branch: 3.5
parent: 97236:6fd69aeb8a3b
user: Yury Selivanov <yselivanov at sprymix.com>
date: Tue Aug 04 12:42:20 2015 -0400
summary:
whatsnew/3.5: Mention PEP 448
files:
Doc/whatsnew/3.5.rst | 43 ++++++++++++++++++++++++++++++++
1 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -203,6 +203,49 @@
:pep:`465` -- A dedicated infix operator for matrix multiplication
+PEP 448 - Additional Unpacking Generalizations
+----------------------------------------------
+
+This PEP proposes extended usages of the ``*`` iterable unpacking
+operator and ``**`` dictionary unpacking operators
+to allow unpacking in more positions, an arbitrary number of
+times, and in additional circumstances. Specifically,
+in function calls, in comprehensions and generator expressions, and
+in displays.
+
+Function calls are proposed to support an arbitrary number of
+unpackings rather than just one::
+
+ >>> print(*[1], *[2], 3)
+ 1 2 3
+ >>> dict(**{'x': 1}, y=2, **{'z': 3})
+ {'x': 1, 'y': 2, 'z': 3}
+
+Unpacking is proposed to be allowed inside tuple, list, set,
+and dictionary displays::
+
+ >>> *range(4), 4
+ (0, 1, 2, 3, 4)
+ >>> [*range(4), 4]
+ [0, 1, 2, 3, 4]
+ >>> {*range(4), 4}
+ {0, 1, 2, 3, 4}
+ >>> {'x': 1, **{'y': 2}}
+ {'x': 1, 'y': 2}
+
+In dictionaries, later values will always override earlier ones::
+
+ >>> {'x': 1, **{'x': 2}}
+ {'x': 2}
+
+ >>> {**{'x': 2}, 'x': 1}
+ {'x': 1}
+
+.. seealso::
+
+ :pep:`448` -- Additional Unpacking Generalizations
+
+
PEP 471 - os.scandir() function -- a better and faster directory iterator
-------------------------------------------------------------------------
--
Repository URL: https://hg.python.org/cpython
More information about the Python-checkins
mailing list