[Python-ideas] get() method for list and tuples

[Ethan Furman]

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:

> 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.

>> - 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.

> - 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.

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.

--
~Ethan~