PEP 378: Format Specifier for Thousands Separator

[Carlos Nepomuceno]

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> To: python-list at python.org
> From: tjreedy at udel.edu
[...]
>> It's a conflict in the design. A tuple is used to supply multiple
>> arguments to the % operator. So if you want to have a tuple as the
>> first argument, you need to enclose it in another tuple.
>
> The problem is that interpolating 1 to many items into a string is *not*
> a binary operation. The needed hack to pretend that it is, using a tuple
> to represent multiple items rather than just itself, was one of the
> reasons for making string formatting a honest function, where multiple
> items to be formatted are passed as multiple arguments.

Thanks so much guys! Now I understand why some people hate %-formatting!

I don't think that's a problem because there's no format specifier for tuples in the %-formatting definition[1].
So it's up to the user to make the necessary conversion.

I still love the %-formatting style!

Can str.format() do the following?

f = '%d %d %d'
v = '1,2,3'
print f % eval(v)

If yes, how?


[1] http://docs.python.org/2/library/stdtypes.html#string-formatting