input: Write a function to print a staircase of height 'n', where n is an integer. The staircase should have '#' characters for the steps and spaces for the left alignment.
  def staircase(n): 
      for i in range(0, n): 
          for j in range(0, n - i - 1): 
              print(end=" ") 
          for j in range(0, i + 1): 
              print("#", end="") 
          print("\r") 
  
  assert staircase(5) == None
  assert staircase(3) == None
  assert staircase(0) == None
output: def staircase(n): 
      for i in range(n): 
          print(' ' * (n - i - 1) + '#' * (i + 1))