[Python-ideas] "any" and "all" support multiple arguments

[Nick Coghlan]

On 1 August 2017 at 23:43, Ned Batchelder <ned at nedbatchelder.com> wrote:
> I find it frustrating that they always return booleans.  It would be more
> useful if any() returned the first true value it finds.  This seems like a
> backward-compatible-enough change to me... :)

While I'm not sure how to interpret that smiley, I figure it's worth
making it explicit that this is decidedly *not* true given
type-dependent serialisation protocols like JSON:

    >>> import json
    >>> class MyClass:
    ...     def __bool__(self):
    ...         return True
    ...
    >>> json.dumps(any([MyClass()]))
    'true'
    >>> json.dumps(MyClass())
    Traceback (most recent call last):
      ...
    TypeError: Object of type 'MyClass' is not JSON serializable

The idea of elevating first_true from its current status as an
itertools recipe to actually being an itertools module API has
certainly come up before, though.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia