This is actually an exercise in Jeff Friedl's Mastering Regular Expressions.
His final reccomendation is to skip the sprintf alltogether and just use
$percent_change =~ s/(\.\d\d(?>[1-9]?))\d+/$1/

[download]
Which always keeps 2 digits, i.e. 2.500 => 2.50.
If you don't wan that to happen, use 
$percent_change =~ s/(\.\d(?>[1-9]{0,2}))\d+/$1/

[download]



Code is (almost) always untested.
http://www.justicepoetic.net/

In reply to Re: Deleting trailing 0's after using sprintf by jweed
in thread Deleting trailing 0's after using sprintf by Popcorn Dave

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