On Thursday, July 21, 2016 at 10:24:42 AM UTC+5:30, Pavol Lisy wrote:
On 7/20/16, Danilo J. S. Bellini <danilo....@gmail.com> wrote:

> 4. Unicode have more than one codepoint for some symbols that look alike,
> for example "Σ𝚺𝛴𝜮𝝨𝞢" are all valid uppercase sigmas. There's also "∑",
> but this one is invalid in Python 3. The italic/bold/serif distinction
> seems enough for a distinction, and when editing a code with an Unicode
> char like that, most people would probably copy and paste the symbol
> instead of typing it, leading to a consistent use of the same symbol.

I am not sure what do you like to say, so for sure some info:

PEP-3131 (https://www.python.org/dev/peps/pep-3131/): "All identifiers
are converted into the normal form NFKC while parsing; comparison of
identifiers is based on NFKC."

From this point of view all sigmas are same:

  set(unicodedata.normalize('NFKC', i) for i in "Σ𝚺𝛴𝜮𝝨𝞢")  == {'Σ'}


>>> Σ = 1
>>> 𝚺 = Σ + 1
>>> 𝛴

But not enough

>>> А = 1
>>> A = A + 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'A' is not defined

Moral: The coarser the equivalence-relation the better (within reasonable limits!)
NFKC-equality i coarser than literal-codepoint equality.  ∴ Better
But not coarse enough.  After all identifiers are meant to identify!