Why Python 3?

[wxjmfauth]

Le mardi 22 avril 2014 08:30:45 UTC+2, Rustom Mody a écrit :
@ rusy

"Ive reworded it to make it clear that I am referring to the

character-sets and not encodings."

Very good, excellent, comment. An healthy coding scheme can only
work properly with a unique characters set and the coding is achieved
with the help of a unique operator. There is no other way to do it
and that's the reason why we have to live today with all these
coding schemes (unicode or not). Note: A coding scheme can be
much more complex than the coding of "raw" characters (eg. CID
fonts).

"So instead of using λ (0x3bb) we should use ð€ (0x1d740)or something thereabouts like ðœ†"

This is a very good understanding of unicode. The letter lambda
is not the mathematical symbole lambda. Another example,
the micro sign is not the greek letter mu which is not the mathematical
mu. Shorly, it's maybe not a bad idea to use a plain ascii "lambda"
instead of a wrong unicode point.

jmf

 

[Rustom Mody]

I'm reminded of this satire:
http://www.ojohaven.com/fun/spelling.html

Ha Ha!! Thanks much for that.

Ive been looking for that for years but had no starting point for a
search
[For some reason I always thought it was Bernard Shaw]

 

[Steven D'Aprano]

Le mardi 22 avril 2014 08:30:45 UTC+2, Rustom Mody a écrit :
@ rusy

character-sets and not encodings."

Very good, excellent, comment. An healthy coding scheme can only work
properly with a unique characters set and the coding is achieved with
the help of a unique operator. There is no other way to do it and that's
the reason why we have to live today with all these coding schemes
(unicode or not). Note: A coding scheme can be much more complex than
the coding of "raw" characters (eg. CID fonts).

For those who cannot see them, they are:

py> unicodedata.name('\U0001d740')
'MATHEMATICAL BOLD ITALIC SMALL LAMDA'
py> unicodedata.name('\U0001d706')
'MATHEMATICAL ITALIC SMALL LAMDA'


("LAMDA" is the official Unicode name for Lambda.)

This is a very good understanding of unicode. The letter lambda is not
the mathematical symbole lambda. Another example, the micro sign is not
the greek letter mu which is not the mathematical mu.

Depends what you mean by "is not". The micro sign is a legacy
compatibility character, we shouldn't use it except for compatibility
with legacy (non-Unicode) character sets. Instead, we should use the NFKC
or NFKD normalization forms to convert it to the recommended character.


py> import unicodedata
py> a = '\N{GREEK SMALL LETTER MU}' # Preferred
py> b = '\N{MICRO SIGN}' # Legacy
py> a == b
False
py> unicodedata.normalize('NFKD', b) == a
True
py> unicodedata.normalize('NFKC', b) == a
True

As for the mathematical mu, there is no separate Unicode "maths symbol
mu" so far as I am aware. One would simply use '\N{MICRO SIGN}' or
'\N{GREEK SMALL LETTER MU}' to get a μ.

Likewise, the λ used in mathematics is the Greek letter λ, not a separate
symbol, just like the Latin letter x and the x used in mathematics are
the same.

 

[wxjmfauth]

Le mardi 22 avril 2014 14:21:40 UTC+2, Steven D'Aprano a écrit :

For those who cannot see them, they are:



py> unicodedata.name('\U0001d740')

'MATHEMATICAL BOLD ITALIC SMALL LAMDA'

py> unicodedata.name('\U0001d706')

'MATHEMATICAL ITALIC SMALL LAMDA'





("LAMDA" is the official Unicode name for Lambda.)










Depends what you mean by "is not". The micro sign is a legacy

compatibility character, we shouldn't use it except for compatibility

with legacy (non-Unicode) character sets. Instead, we should use the NFKC

or NFKD normalization forms to convert it to the recommended character.





py> import unicodedata

py> a = '\N{GREEK SMALL LETTER MU}' # Preferred

py> b = '\N{MICRO SIGN}' # Legacy

py> a == b

False

py> unicodedata.normalize('NFKD', b) == a

True

py> unicodedata.normalize('NFKC', b) == a

True



As for the mathematical mu, there is no separate Unicode "maths symbol

mu" so far as I am aware. One would simply use '\N{MICRO SIGN}' or

'\N{GREEK SMALL LETTER MU}' to get a μ.



Likewise, the λ used in mathematics is the Greek letter λ, not a separate

symbol, just like the Latin letter x and the x used in mathematics are

the same.

Normalization is working fine, but it proofs nothing, it
has to use some convention.

There are several code points ranges (latin + greek), which can
be used for mathematical purpose (different mu's).

If you are interested, search for "unimath-symbols.pdf"
on CTAN (I have all this stuff on my hd).

....
"Likewise, the λ used in mathematics is the Greek letter λ, not aseparate
symbol, just like the Latin letter x and the x used in mathematics are
the same. "... just like the Latin letter x and the x used in mathematics
are the same.
....

Oh! Definitively not. A tool with an unicode engine able to
produce "math text" will certainly not use the same code point
for a "textual x" or for a "mathematical x", even if one
enter/type/hit the same "x".

To be exaggeratedly stict, the real question is to know
if a used "lambda" or "x" belongs to a "math unicode range"
or not. This is quite a different approach. (Please no
confusion with a "text litteral variable x").

A text processing tool will notice the difference, it will
use different fonts.

jmf

 

[Rustom Mody]

I'm reminded of this satire:
http://www.ojohaven.com/fun/spelling.html

At the risk of 'explaining the joke' I believe it becomes comical due
to the cumulating effect of suggesting ↠for assignment and then using that.
Since I dont like its look in any fonts that I can check, I am returning the
(subsequent) examples to to good (or bad) old =

Also the λ is unnecessarily contentions. Been replaced by more
straightforward introductory examples.

 

[Thomas Lehmann]

Hi,

I can't give you the advise for a concrete version anyway there are lot of arguments given by the other posters. BUT there is a way how you can circumvent the problem to some extend:

Are you intending to use Jenkins? I don't want to convince you here why to use Jenkins but maybe I don't need to and THEN you just install the ShiningPanda plugin and each time your project is build automatically because of achange all tests are running across multiple Python versions. This way youwon't have too many problems to switch to another newer Python version. Keep the build "green".