input: 
  def get_row(lst, x):
      """
      You are given a 2 dimensional data, as a nested lists,
      which is similar to matrix, however, unlike matrices,
      each row may contain a different number of columns.
      Given lst, and integer x, find integers x in the list,
      and return list of tuples, [(x1, y1), (x2, y2) ...] such that
      each tuple is a coordinate - (row, columns), starting with 0.
      Sort coordinates initially by rows in ascending order.
      Also, sort coordinates of the row by columns in descending order.
      
      Examples:
      get_row([
        [1,2,3,4,5,6],
        [1,2,3,4,1,6],
        [1,2,3,4,5,1]
      ], 1) == [(0, 0), (1, 4), (1, 0), (2, 5), (2, 0)]
      get_row([], 1) == []
      get_row([[], [1], [1, 2, 3]], 3) == [(2, 2)]
      """
  
output: 
      coordinates = []
      for row_index, row in enumerate(lst):
          for col_index, value in enumerate(row):
              if value == x:
                  coordinates.append((row_index, col_index))
      coordinates.sort(key=lambda coord: (coord[0], -coord[1]))
      return coordinates
  