On 2016-07-03 19:39, John Ladasky wrote:
On Sunday, July 3, 2016 at 12:42:14 AM UTC-7, Chris Angelico wrote:
On Sun, Jul 3, 2016 at 4:58 PM, John Ladasky wrote:
Very good question! The detaily answer is here:
https://docs.python.org/3/reference/lexical_analysis.html#identifiers
> A philosophical question. Why should any character be excluded from a
variable name, besides the fact that it might also be an operator?
In a way, that's exactly what's happening here. Python permits certain
categories of character as identifiers, leaving other categories
available for operators. Even though there aren't any non-ASCII
operators in a vanilla CPython, it's plausible that someone could
create a Python-based language with more operators (eg ≠ NOT EQUAL TO
as an alternative to !=), and I'm sure you'd agree that saying "≠ = 1"
is nonsensical.
I agree that there are some characters in the Unicode definition that could (should?) be operators and, as such,
disallowed in identifiers. "≠", "≥" and "√" come to mind. I don't know whether the
Unicode "character properties" are assigned to the characters in a way that would be satisfying to the needs
of programmers. I'll do some reading.
Symbols like that are a bit of a
grey area, so you may find that you're starting a huge debate :)
Oh, I can see that debate coming. I know that not all of these characters are
easily TYPED, and so I have to reach for a Unicode table to cut and paste them.
But once but and pasted, they are easily READ, and that's a big plus.
Here's another worm for the can. Would you rather read this...
d = sqrt(x**2 + y**2)
...or this?
d = √(x² + y²)
It's easy to read something as simple like that, but it's harder when
the exponent is more than a number or a variable. And what about a**b**c?
Not to mention the limited number of superscript codepoints available...
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