[Tutor] print as columns [using apply()]

[Mike Serpa]

> 
> Danny Yoo wrote
> > The guilt is not really on apply(), but max() --- max() can't
> handle a
> > single argument: it always assumes that it works with at least two:
> > 
> [snipped]
> > 
> > On the other hand, reduce() should work on this pathological
> example:
> > 
> > ###
> > >>> reduce(max, map(len, ([1],)))
> > 1
> > ###
> > 
> > 
> > I must remind myself to test my programs with small "boundary"
> cases, just
> > to make sure nothing leaks out... *grin*
> 
> Actually, on this, I'm almost surprised.  I'd think that you would
> have
> to add the trailing initial value to reduce.
> 
> >>> reduce(max, map(len, ([1],)), 0)
> 
> Interestingly, max((1,)) returns 1 (yikes).
> 
>   -Arcege
> 

Okay, I think I've got it now.  You still don't need reduce or apply.

a = [1,2,3]
b = [4,5,6,7]
c = [8,9]

max(map(len, (a, b, c)))
# or max(map(len, (a,)))


still works even if there is only one list.
the map function returns a list e.g. [3,4,2]  # or [3]
max([3]) works fine.

If it's really preferable to use reduce or apply here please explain it
to me because I don't get it.

Mike



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