input: Write a function to print a Pascal triangle up to the given number of rows. If the number of rows is less than or equal to zero, print an empty line.
  
  def PascalTriangle(n):
      if n <= 0:
          print()
          return
  
      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()
          
  assert PascalTriangle(5) == None
  assert PascalTriangle(0) == None
  assert PascalTriangle(-1) == None
output: def PascalTriangle(n):
      if n <= 0:
          print()
          return
  
      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()