input: Write a function to print a staircase of height 'n' where n is an integer input. Each step of the staircase should be made of '#' characters with the right alignment. If n is an integer input, the function should generate and print the staircase.
  assert staircase(5)
  # Output should be:
  #     #
  #    ##
  #   ###
  #  ####
  # #####
  assert staircase(3)
  # Output should be:
  #   #
  #  ##
  # ###
  assert staircase(0)
  # Output should be:
  # (nothing should be printed)
  assert staircase(-1)
  # Output should be:
  # (nothing should be printed)
  assert staircase(1)
  # Output should be:
  # #
output: def staircase(n):
      for i in range(1, n + 1):
          print(' ' * (n - i) + '#' * i)