input: 
  from typing import List
  
  def PascalTriangle(n: int) -> List[List[int]]:
      """ Generate a Pascal triangle with 'n' rows and return it as a list of lists.
      >>> PascalTriangle(5)
      [[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]
      >>> PascalTriangle(1)
      [[1]]
      >>> PascalTriangle(0)
      []
      """
      if n == 0:
          return []
      
      triangle = [[1]]
      
      for i in range(1, n):
          prev_row = triangle[-1]
          new_row = [1]
          
          for j in range(1, i):
              new_row.append(prev_row[j-1] + prev_row[j])
          
          new_row.append(1)
          triangle.append(new_row)
      
      return triangle
  
output:     if n == 0:
          return []
      
      triangle = [[1]]
      
      for i in range(1, n):
          prev_row = triangle[-1]
          new_row = [1]
          
          for j in range(1, i):
              new_row.append(prev_row[j-1] + prev_row[j])
          
          new_row.append(1)
          triangle.append(new_row)
      
      return triangle