which is better, string concatentation or substitution?

[John Salerno]

Roy Smith wrote:

> One may be marginally faster, but they both require copying the source 
> string, and are thus both O(n).

Sorry, I'm not familiar with the O(n) notation.

> If you're just doing one or a small fixed 
> number of these, it really doesn't matter.  Pick whichever one you think is 
> easier to read.

Thanks guys. I have a handful of methods that each do this task once per 
call, so I suppose this counts as not a lot, at least not at one time. 
And it seems like a good point that the real problem could be constantly 
concatenating with self.source, rather than the smaller pieces being put 
together.