input: 
  from typing import List
  
  
  def PascalTriangle(n: int):
      """
      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]
          for i in range(0, line + 1):
              print(arr[i], end=" ")
          print()
  
  # Driver Code
  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]
          for i in range(0, line + 1):
              print(arr[i], end=" ")
          print()
  