clarification

[samwyse]

Scott David Daniels wrote:
>   lefts = set()
>   rights = set()
>   with open('sheet1', 'r') as fh:
>       for line in fh:
>           trimmed = line.strip()
>           if trimmed: # Skip blanks (file end often looks like that)
>               left, right = line.strip().split('\t')
>               lefts.add(left)
>               rights.add(right)
>   result = lefts & rights
> 
> -Scott

   # change to however many columns may later exist
   cols = [ set() for i in range(0, 2) ]
   with open('sheet1', 'r') as fh:
       for line in fh:
           for col, data in zip(cols, line.strip().split('\t')):
               col.add(data)
   result = cols[0] & cols[1]