"andrew cooke" <and...@acooke.org> wrote:
> Carl Banks wrote:
> > import collections
> > import itertools
> >
> > def createInitialCluster(fileName):
> > fixedPoints = []
> > # quantization is a dict that assigns sequentially-increasing
> > numbers
> > # to values when reading keys that don't yet exit
> > quantization = defaultdict.collections(itertools.count().next)
> > with open(fileName, 'r') as f:
> > for line in f:
> > dimensions = []
> > for s in line.rstrip('\n').split(","):
> > if isNumeric(s):
> > dimensions.append(float(s))
> > else:
> > dimensions.append(float(quantization[s]))
> > fixedPoints.append(Point(dimensions))
> > return Cluster(fixedPoints)
>
> nice reply (i didn't know defaultdict worked like that - very neat).
>
> two small things i noticed:
>
> 1 - do you need a separate quantization for each column? the code above
> might give, for example, non-contiguous ranges of integers for a
> particular column if a string occurs ("by accident" perhaps) in more than
> one.
>
> 2 - don't bother with isNumeric. just return the cast value or catch the
> exception:
>
> [...]
> try:
> dimensions.append(float(s))
> except:
> dimensions.append(float(quantization[s]))
No, no, no; never use a bare except! :)
Do it MRAB's way and catch ValueError.
--
R. David Murray http://www.bitdance.com
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