in place list modification necessary? What's a better idiom?

[Peter Otten]

Peter Otten wrote:

> MooMaster wrote:
> 
>> Now we can't calculate a meaningful Euclidean distance for something
>> like "Iris-setosa" and "Iris-versicolor" unless we use string-edit
>> distance or something overly complicated, so instead we'll use a
>> simple quantization scheme of enumerating the set of values within the
>> column domain and replacing the strings with numbers (i.e. Iris-setosa
>> = 1, iris-versicolor=2).
> 
> I'd calculate the distance as
> 
> def string_dist(x, y, weight=1):
>     return weight * (x == y)

oops, this must of course be (x != y).
 
> You don't get a high resolution in that dimension, but you don't introduce
> an element of randomness, either.
> 
> Peter
>