[Python-Dev] PEP 572: Assignment Expressions

[Stephen J. Turnbull]

Chris Angelico writes:

 > There's that word "readability" again. Sometimes I wish the Zen of
 > Python didn't use it, because everyone seems to think that "readable"
 > means "code I like".

Hey, man, that hurts.  Some of us not only *have* precise statements
of the aspects of readability we invoked, but we *provided* them in
our posts.

I sympathize that you get tired of the repetitions of various claims
about readability, as well as the proliferation of purely subjective
claims about it, but that doesn't mean they deserve to be dismissed
this way.

That said, subjectivity is a real problem, and it's not a PEP
protagonist's responsibility to deal with it.  I would like to
recommend that posters who want to make claims about "readability"
remember that it's one aspect of Pythonic language design out of many,
and that it is a complex concept itself.  A claim about readability is
a claim about an aspect of the *value* of a construct, but the word
"readability" alone is too subjective to explain *why* it has (or
lacks) that value.

If you can't describe, let alone define, what you mean by "readable",
but still feel strongly enough to post, think whether you really mean
that word.  If so, apologize for that lack, because PEP protagonists
have no obligation to figure out what you can't.  If not, find another
word to express the feeling.  Or postpone posting until you have a
description or better word.

Language design has a lot of these words involving complexity and
subjectivity: readability, expressiveness, power.  Remember that your
"vote" counts even when subjective: you don't have to justify your
likes.  But if it's personal, you can express that succinctly with
+1/-1.  If you want to claim that the subjective feeling is common to
many users of Python, you need to communicate it.  Try to define the
aspect you're using.  Do so explicitly, unless the definition you're
using was given already in a recent post and is current in the thread.

Steve