input: Write a function to print a staircase of height 'n', where n is an integer. The staircase should be right-aligned, with each row containing a number of '#' characters equal to the row number (starting from 1). If n is 0 or negative, the function should print nothing.
  
  def print_staircase(n):
      if n <= 0:
          return
      for i in range(1, n + 1):
          print(" " * (n - i) + "#" * i)
  
  assert print_staircase(5)
  assert print_staircase(3)
  assert print_staircase(0) == None
  assert print_staircase(-1) == None
  assert print_staircase(1)
output: def print_staircase(n):
      if n <= 0:
          return
      for i in range(1, n + 1):
          print(" " * (n - i) + "#" * i)