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Questions tagged [pep448]

Questions related to PEP 448: Additional Unpacking Generalizations, used for unpacking iterables and mappings within literal tuples, lists, sets and dicts using * and **

For questions related to PEP 448: Additional Unpacking Generalizations, used for unpacking iterables and mappings within literal tuples, lists, sets and dicts

6 questions
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Python: Splat/unpack operator * in python cannot be used in an expression?

Does anybody know the reasoning as to why the unary (*) operator cannot be used in an expression involving iterators/lists/tuples? Why is it only limited to function unpacking? or am I wrong in thinking that? For example: >>> [1,2,3, *[4,5,6]] File…
Har
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asterisk in tuple, list and set definitions, double asterisk in dict definition

I'm playing now with Python 3.5 interpreter and found very interesting behavior: >>> (1,2,3,"a",*("oi", "oi")*3) (1, 2, 3, 'a', 'oi', 'oi', 'oi', 'oi', 'oi', 'oi') >>> [1,2,3,"a",*range(10)] [1, 2, 3, 'a', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>>…
George Sovetov
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Weird unpacking in list comprehension

I was watching a lecture from David Beazley. At minute 23:20 he does some "magic" with unpacking that I am having hard time understanding. The "magic line" is fail = [ { **row, 'DBA Name': row['DBA Name'].replace("'",'').upper() } for row in fail…
alec_djinn
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What does the * sign mean in the following code?

I was solving a programming puzzle and came across this solution by someone. I don't understand why the * is used. a = [*map(len,input().replace(" ","").replace("12","1 2").replace("21","2 1").split(" "))]
govind
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Additional Unpacking Generalizations (PEP 448) with variable number of elements

The acceptance of PEP 448 has introduced Additional Unpacking Generalizations in Python 3.5. For example: >>> l1 = [1, 2, 3] >>> l2 = [4, 5, 6] # unpack both iterables in a list literal >>> joinedList = [*l1, *l2] >>> print(joinedList) [1, 2, 3, 4,…
Jean-Francois T.
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Whats the difference between * and list() in Python?

I have noticed that some people use * to turn something into a list. I initially only knew of putting list(x) around the object, but doing *x also seems to work. Are they equivalent? For example, both *Counter(list).values() and…
user832075
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