On 16.10.2016 07:08, David Mertz wrote:
In case it wasn't entirely clear, I strongly and vehemently opposed
this unnecessary new syntax. It is confusing, bug prone, and would be
difficult to teach.
As this discussion won't come to an end, I decided to consult my girlfriend.
I started with (btw. she learned basic Python to solve some math quizzes):
Let's install a list in another one.
[2, 3, 4, 5]
>>> ['a', meine_liste, 'b']
['a', [2, 3, 4, 5], 'b']
Maybe, we want to remove the brackets.
>>> ['a', *meine_liste, 'b']
['a', 2, 3, 4, 5, 'b']
Now, the problem of the discussion is the following:
>>> [(i,i,i) for i in range(4)]
[(0, 0, 0), (1, 1, 1), (2, 2, 2), (3, 3, 3)]
Let's remove these inner parentheses again.
>>> [*(i,i,i) for i in range(4)]
File "<stdin>", line 1
SyntaxError: iterable unpacking cannot be used in comprehension
Some guy wanted to remove that restriction.
I said a teacher contributed to the discussion and he finds this too
complicated and confusing and does not even teach * in list displays at
all. Her reaction was hilarious:
"Whom does he teach? Children?"
Me: "What? No, everybody I think. Why?"
She: "It's easy enough to remember what the star does."
She also asked what would the alternative would look like. I wrote:
>>> from itertools import chain
>>> list(chain.from_iterable((i,i,i) for i in range(4)))
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3]
Her reaction was like: "That's supposed to be easy to remember? I find
the star easier."
In the end, she also added: "Not everybody drives a car but they still
PS: off to the weekend. She's already complaint that I should spend less
time inside my mailbox and more with her. ;)
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