Using namedtuples field names for column indices in a list of lists

Deborah Swanson python at deborahswanson.net
Mon Jan 9 16:52:01 EST 2017


breamoreboy at gmail.com wrote, on January 09, 2017 8:32 AM
> 
> On Monday, January 9, 2017 at 2:22:19 PM UTC, Tim Chase wrote:
> > On 2017-01-08 22:58, Deborah Swanson wrote:
> > > 1) I have a section that loops through the sorted data, compares
two 
> > > adjacent rows at a time, and marks one of them for deletion if the

> > > rows are identical.
> > > and my question is whether there's a way to work with two adjacent

> > > rows without using subscripts?
> > 
> > I usually wrap the iterable in something like
> > 
> >   def pairwise(it):
> >     prev = next(it)
> >     for thing in it:
> >       yield prev, thing
> >       prev = thing
> > 
> >   for prev, cur in pairwise(records):
> >     compare(prev, cur)
> > 
> > which I find makes it more readable.
> > 
> > -tkc
> 
> Or from 
> https://docs.python.org/3/library/itertools.ht> ml#itertools-recipes:-
> 
> def pairwise(iterable):
>     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
>     a, b = tee(iterable)
>     next(b, None)
>     return zip(a, b)
> 
> This and many other recipes are available in the 
> more-itertools module which is on pypi.

Thanks, I'll keep this since I seem to do pairwise comparisons a lot.
I'm going to try using set or OrderedDict for the current problem, per
Peter's suggestion, but if I can't make that work, this surely will.



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