[Python-Dev] summary of transitioning from % to {} formatting (original) (raw)

Nick Coghlan ncoghlan at gmail.com
Mon Oct 5 22:41:25 CEST 2009

Barry Warsaw wrote:

On Oct 4, 2009, at 4:11 AM, Nick Coghlan wrote:

Barry Warsaw wrote: I also don't think this is a case of anti-TOOWTDI. For most situations {}-strings are great (IMO), but in the specific translation domain, I suspect $-strings are still better.

I agree that keeping string.Template around is valid due to its focus on being very simple to use (especially for non-coders producing translation templates) However, string.Template is already set up to work for the relevant APIs in that domain so I don't think it will really be affected by any changes to the underlying language and library support for brace formatting. What if you wanted to translate log messages? Printing to a StringIO first really isn't a very good solution.

Oh, I see what you meant now - you were pointing out that lazy formatting APIs (such as logging) already don't work properly for alternative formatting mechanisms (such as string.Template).

(Although printing to a String IO doesn't seem necessary - simply pre-formatting the message seems like it should work, just as preformatting brace formatted messages already works today).

The idea of adding an optional "fmt_style" callable to these APIs (defaulting to None, which would imply the use of the mod operator) is becoming more appealing...

Cheers, Nick.

-- Nick Coghlan | ncoghlan at gmail.com | Brisbane, Australia

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