def flatten_list(my_list):
      if my_list == []:
          return my_list
      if isinstance(my_list[0], list):
          return flatten_list(my_list[0]) + flatten_list(my_list[1:])
      return my_list[:1] + flatten_list(my_list[1:])
  my_list = [[1,2],[3,4], [90, 11], [56, 78], [[34,56]]]
  print("The list is :")
  print(my_list)
  print("The list after flattening is : ")
  print(flatten_list(my_list))

  The list is :
  [[1, 2], [3, 4], [90, 11], [56, 78], [[34, 56]]]
  The list after flattening is :
  [1, 2, 3, 4, 90, 11, 56, 78, 34, 56]