Guido rethinking removal of cmp from sort method

Terry Reedy tjreedy at
Fri Apr 1 18:59:05 CEST 2011

On 4/1/2011 3:45 AM, Paul Rubin wrote:

> Removing cmp certainly isn't the most disruptive change of Python 3,

That was almost certainly the ascii to unicode switch for strings. It is 
still not quite complete in 3.2 but should be pretty well ironed out in 3.3.

> but it seems like the one with the least benefit.

Since the set of changes was finite, there *must* be (at least) one with 
the lowest benefit/cost ratio. The removal of list.sort(cmp) may well be 
that one. Certainly, reasonable people can disagree as to whether the 
ratio is above or below 1.0.

If cmp had not been removed, some other change would have been the worst 
in this respect, and possibly the subject of a thread like this.

Terry Jan Reedy

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