input: 
  def PascalTriangle(n):
      """ Generate and print a Pascal triangle of `n` rows.
      >>> PascalTriangle(5)
      1 
      1 1 
      1 2 1 
      1 3 3 1 
      1 4 6 4 1 
      """
      arr = [0 for i in range(n)] 
      for line in range(0, n): 
          for i in range(0, line + 1): 
              if i == 0 or i == line: 
                  arr[i] = 1
              else: 
                  arr[i] = arr[i] + arr[i - 1] 
              print(arr[i], end=" ") 
          print() 
  
  # Test case
  n = 5
  PascalTriangle(n)
  
output:     arr = [0 for i in range(n)] 
      for line in range(0, n): 
          for i in range(0, line + 1): 
              if i == 0 or i == line: 
                  arr[i] = 1
              else: 
                  arr[i] = arr[i] + arr[i - 1] 
              print(arr[i], end=" ") 
          print()