Syntax across languages

[Alex Martelli]

<skip at pobox.com> wrote:

>     Alex> I've seen enough occurrences of "lambda x: x" in Python code with
>     Alex> a generally functional style that I'd love to have
>     Alex> operator.identity (and a few more trivial functions like that) for
>     Alex> readability;-)
> 
> But, but, but [Skip gets momentarily apoplectic, then recovers...]
> "operator.identity" is way more to type than "lambda x: x".  Plus you have
> to remember to import the operator module. <0.5 wink>

But, it's way more readable, IMHO.


> Not to mention which (from "pydoc operator"):
> 
>     [The operator module] exports a set of functions implemented in C
>     corresponding to the intrinsic operators of Python.
> 
> Last time I checked, Python didn't have an intrinsic "identity" operator.

attrgetter and itemgetter don't exactly correspond to "intrinsic
operators", either (getitem, and the built-in getattr, are more like
that)... yet module operator exports them today, offering more readable
(and faster) alternatives to "lambda x: x[y]" and "lambda x: getattr(x,
y)".

 
> For which reason, I'd be -1 on the idea of an identity function, certainly
> in the operator module.

I'm not at all wedded to having 'identity' in the operator module (which
may arguably be the wrong placement for 'attrgetter' and 'itemgetter'
too).  But identity is a useful primitive for a functional style of
Python programming, so having it SOMEwhere would be nice, IMHO.


Alex