code: def _parse_edge_weight(f, nodes):
      
      matrix = []
  
      n = 0
  
      for line in f:
          line = strip(line)
  
          regex = re.compile(r'\s+')
  
          row = regex.split(line)
  
          matrix.append(row)
  
          n = n + 1
  
          if n == nodes:
              break
  
      if n != nodes:
          raise ParseException('Missing {} nodes definition from section EDGE_WEIGHT_SECTION'.format(nodes - n))
  
      return matrix
docs: Parse TSPLIB EDGE_WEIGHT_SECTION from file f
  
      Supports only FULL_MATRIX for now