Need max values in list of tuples, based on position

[DFS]

On 11/11/2022 7:50 AM, Stefan Ram wrote:
> Pancho <Pancho.Jones at proton.me> writes:
>> def build_max_dict( tups):
>>      dict = {}
>>      for (a,b) in tups:
>>          if (a in dict):
>>              if (b>dict[a]):
>>                  dict[a]=b
>>          else:
>>              dict[a]=b
>>      return(sorted(dict.values()))
> 
>    Or,
> 
> import itertools
> import operator
> 
> def build_max_dict( tups ):
>      key = operator.itemgetter( 0 )
>      groups = itertools.groupby( sorted( tups, key=key ), key )
>      return set( map( lambda x: max( x[ 1 ])[ 1 ], groups ))

FYI, neither of those solutions work:

Pancho: 11, 12, 41
You   : 41, 11, 12

The answer I'm looking for is 11,41,12


Maybe a tuple with the same info presented differently would be easier 
to tackle:

orig:
[(0, 11), (1, 1),  (2, 1),
  (0, 1),  (1, 41), (2, 2),
  (0, 9),  (1, 3),  (2, 12)]

new: [(11,1,1),
       (1,41,2),
       (9,3,12)]

I'm still looking for the max value in each position across all elements 
of the tuple, so the answer is still 11,41,12.


Edit: found a solution online:
-----------------------------------------------------------------
x = [(11,1,1),(1,41,2),(9,3,12)]
maxvals = [0]*len(x[0])
for e in x:
	maxvals = [max(w,int(c)) for w,c in zip(maxvals,e)]
print(maxvals)
[11,41,12]
-----------------------------------------------------------------

So now the challenge is making it a one-liner!


Thanks