On Fri, Jan 04, 2019 at 06:15:11PM -0600, Abe Dillon wrote:
> Sure everyone knows what it means, but it's meaning is essentially useless
> because the default assumption when you encounter a variable you don't
> know, is that you shouldn't overwrite it. If you found a module-level
> variable in Pandas named cucumber, would you immediately assume you can
> write whatever value you want to pandas.cucumber because it isn't in all
> caps?
Code is read more often than it is written.
The important question is rarely "can I overwrite random variables?" but
is usually "what is the value of this variable right now?".
If I see a call like:
function(cucumber)
I may have no idea what cucumber holds, or where to find its binding. I
may have to work hard to determine
(1) where it is initially bound;
(2) whether or not it has been, or could be, rebound to something else;
(3) and what value it holds at the time it is passed to the function.
If cucumber is a *variable*, that's kind of unavoidable, its part of
what makes programming so ~~frustrating~~ fun and why we have debuggers,
tracing and the venerable old technique of inserting print() calls to
find out what's going on in our code.
But if I see:
function(CUCUMBER)
that tells me that in idiomatic Python code, CUCUMBER is a constant
bound close to the top of the module, and never rebound.
--
Steve
_______________________________________________
Python-ideas mailing list
Python-ideas@python.org
https://mail.python.org/mailman/listinfo/python-ideas
Code of Conduct: http://python.org/psf/codeofconduct/
