[Python-Dev] Python and the Unicode Character Database (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Wed Dec 1 23:32:25 CET 2010

And here, my observation stands: if they wanted to, they currently couldn't - at least not for real numbers (and also not for integers if they want to use grouping). So the presumed application of this feature doesn't actually work, despite the presence of the feature it was supposedly meant to enable. By that argument, English speakers wanting to enter integers using Arabic numerals can't either!

That's correct, and the key point here for the argument. It's just not meant to support localized number forms, but deliberately constrains them to a formal grammar which users using it must be aware of in order to use it.

I'd like to use grouping for large literals, if only I could think of a half-decent syntax, and if only Python supported it. This fails on both counts:

x = 123456789012345

Here you are confusing issues, though: this fragment uses the syntax of the Python programming language. Whether or not the syntax of the float() constructor arguments matches that syntax is also a subject of the debate.

I take it that you speak in favor of the float syntax also being used for the float() constructor.

The lack of grouping and the lack of a native decimal point doesn't mean that the feature "doesn't work" -- it merely means the feature requires some compromise before it can be used.

No, it means that the Python programming language syntax for floating point numbers just doesn't take local notation into account at all. This is not a flaw - it just means that this feature is non-existent.

Now, for the float() constructor, some people in this thread have claimed that it is aimed at people who want to enter numbers in their local spellings. I claim that this feature either doesn't work, or is absent also.

In the same way, if I wanted to enter a number using non-Arabic digits, it works provided I compromise by using the Anglo-American decimal point instead of the European comma or the native decimal point I might prefer.

Why would you want that, if, what you really wanted, could not be done. There certainly is a way to convert strings into floats, and there would be a way if that restricted itself to the digits 0..9. So it can't be the mere desire to convert strings to float that make you ask for non-ASCII digits.

The lack of support for non-dot decimal points is arguably a bug that should be fixed, not a reason to remove functionality.

I keep repeating my two concerns: a) if that was a feature, it is not specified at all in the documentation. In fact, the documentation was recently clarified to deny existence of that feature. b) fixing it will be much more difficult than you apparently think.

Regards, Martin

More information about the Python-Dev mailing list