identity = lambda x: x -- a Pythonic idiom?

[Erik Max Francis]

George Demmy wrote:

> My understanding of Pythonic truth anything other than None, (), [],
> {}, '', and 0 is true. I don't know what mathematical truth is -- got
> a approachable reference for an interested non-mathematician?

When you're using filter, the function you need maps an object to a
truth value, but the identity function maps an object to itself.  In
Python this happens to be the same thing, but what you "really mean" is
lambda x: operator.truth(x).

-- 
 Erik Max Francis / max at alcyone.com / http://www.alcyone.com/max/
 __ San Jose, CA, US / 37 20 N 121 53 W / ICQ16063900 / &tSftDotIotE
/  \ Laws are silent in time of war.
\__/ Cicero
    Esperanto reference / http://www.alcyone.com/max/lang/esperanto/
 An Esperanto reference for English speakers.