How is max supposed to work, especially key.
Terry Reedy
tjreedy at udel.edu
Thu Dec 4 10:47:21 EST 2014
On 12/4/2014 5:35 AM, Albert van der Horst wrote:
> I agree that it is a useful function and that it is doing
> the right thing. What is wrong is the name.
> I refer to the fact that it is not returning the maximum.
> It returns the iterator value that leads to the maximum.
> A function that doesn't return a maximum shouldn't be called
> maximum.
The key function serves the same purpose as with sort. It define a
custom ordering of items, not the values returned. 'x < y' is defined
as key(x) < key(y), where the comparison of keys uses the standard (and
for numbers, natural) built-in ordering. So max returns the max value
according to the order you define with the key function. The default
key is the identity function, so the default order is the builtin order.
--
Terry Jan Reedy
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