Programming intro book ch1 and ch2 (Windows/Python 3) - Request For Comments

[Gregory Ewing]

Mensanator wrote:
> Really? Does that mean you don't use literals, to save the time
> required to convert them to integers?

I think all he means is that when he *does* use a named
constant, he spells it in lower case rather than upper
case, e.g. 'twopi' rather than 'TWOPI'.

I don't think there's anything much wrong with that. It
can be useful sometimes to visually distinguish constants
from variables, but it's not a necessity. Also the all-
uppercase convention isn't the only way to do that -- it's
a C-ism that isn't universally followed in Python. An
alternative often used is just to uppercase the first
character. Python itself uses that for many of its
built-in constants, such as None, True, False.

Arguing that functions are usually constants and should
therefore have uppercase names is missing the point --
everyone expects them to be constant anyway, so there's
no need for a typographical convention to indicate that.
In the rare cases where they're not constant, they can
usually be named in a way that makes this obvious.

(And BTW, looking up a global name is *slower* than using
a literal. Although a local name is probably about the
same speed as a literal, as they're both array accesses.)

-- 
Greg