What is a function parameter =[] for?

[Ian Kelly]

On Wed, Nov 25, 2015 at 7:25 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Nov 26, 2015 at 1:08 PM, Alan Bawden <alan at csail.mit.edu> wrote:
>> (Note that nothing in the documentation I can find actually _guarantees_
>> that a Python implementation will only have one unique empty tuple, but
>> I wouldn't be suprised if the following is nonetheless true in all
>> current implementations:
>>
>>    >>> tuple([]) is tuple([])
>>    True
>>
>> )
>
> Jython 2.5.3 (, Oct 8 2014, 03:39:09)
> [OpenJDK 64-Bit Server VM (Oracle Corporation)] on java1.7.0_85
> Type "help", "copyright", "credits" or "license" for more information.
>>>> tuple([]) is tuple([])
> False
>
> Python 2.7.8 (2.4.0+dfsg-3, Dec 20 2014, 13:30:46)
> [PyPy 2.4.0 with GCC 4.9.2] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>>> tuple([]) is tuple([])
> False

Well, he did say all "current" implementations. CPython 2.7 may still
be supported, but that doesn't make it current. And anything at 2.5 is
just archaic.