input: Write a function to print a Pascal triangle with a given number of rows. If the number of rows is 0, the function should print nothing. If the number of rows is negative, the function should raise a ValueError.
  
  def PascalTriangle(n):
      if n < 0:
          raise ValueError("Number of rows cannot be negative")
        
      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)
  assert PascalTriangle(0)==None
  assert PascalTriangle(-1)==ValueError
output: def PascalTriangle(n):
      if n < 0:
          raise ValueError("Number of rows cannot be negative")
        
      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()