On 03.03.2017 20:35, Ethan Furman wrote:
On 03/03/2017 11:01 AM, Sven R. Kunze wrote:
On 03.03.2017 19:29, Ed Kellett wrote:
The reasons already stated boil down to "lists aren't dicts so they
shouldn't share methods", which seems ill-advised
at best, and "I wouldn't use this".
I wonder if those arguing against it also think dicts should not have
item access:
dicts don't have item access -- they have key access. :wink:
Python doesn't make a difference here. :wink:
https://docs.python.org/3/reference/datamodel.html#object.__getitem__
a[0]
dict or list? Why should it matter?
Because they are different data types with different purposes.
- Which of the existing things (slice + [default], conditional on a
slice, conditional on a len() call) do you think
is the obvious way to do it?
None of them are. Try/except is the most obvious way. But it's tedious.
[my_value] = some_list[offset:offset+1] or [default_value]
No, it's not terribly pretty, but accessing invalid locations on a
list on purpose shouldn't be that common.
When generating data series / running a simulation, at the beginning
there is no data in many lists. Recently, had those issues.
dicts went fine, lists just sucked with all those try/except blocks.
- Are there any examples where list.get would be applicable and not
the obviously best way to do it?
I don't think so. I already have given many examples/ideas of when I
would love to have had this ability. Let me
re-state those and more:
- refactoring (dicts <-> lists and their comprehension counterparts)
dict and list comprehensions are not the same, and adding .get to list
won't make them the same.
Never said they are the same. I said refactoring is easier.
- easier to teach
Having `print` be a statement instead of a function made it easier to
teach but that didn't make it a good idea.
Many people disagree with you on this.
For me to think (list/tuple).get() was needed would be if lots of folk
either cast their lists to dicts or made their own list-dict class to
solve that problem.
The easier solution would be to provide list.get ;-)
Regards,
Sven
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