python 3 problem: how to convert an extension method into a class Method

Robin Becker robin at
Wed Feb 27 12:11:08 CET 2013

On 27/02/2013 10:49, Chris Angelico wrote:
> On Wed, Feb 27, 2013 at 9:36 PM, Robin Becker <robin at> wrote:
>> However, in my case the method takes
>>                        py  C
>> utf8 bytes            50  20 usec
>> unicode               39  15
>> here py refers to a native python method and C  to the extension method
>> after adding to the class. Both are called via an instance of the class.
> Which raises the obvious question: Does it even matter? Will the
> saving of a few microseconds really make a difference? Python's best
> feature is its clarity of code, not its blazing performance; its
> performance goal is "fast enough", and for many MANY purposes, you
> won't be able to tell the difference between that and "awesome". Don't
> sacrifice your code's clarity to the little tin god of efficiency
> until you're sure you actually get something back.
> ChrisA
in fact this is the stringWidth function and it's used thousands of times. I 
think when we did benchmark tests it came out as 1 or 2 as a cpu hog. Since it's 
comparatively easy to code it's an obvious choice to move to C.
Robin Becker

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