text: from pptx import Presentation
  from pptx.dml.color import RGBColor
  from pptx.util import Inches
  from PypptRoadSign.background import Background
  
  BLACK = RGBColor(0, 0, 0)  # 黑色
  WHITE = RGBColor(255, 255, 255)  # 白色
  NAVYBLUE = RGBColor(0, 63, 143)  # 预定的蓝色
  ROUND_DEGREE = 0.05  # 圆角程度调整 0-1
  
  
  class Sign:
      def __init__(self, background_style='default', width=16, height=9):
          prs = Presentation()
          prs.slide_width = Inches(width)  # Slide宽度 16 Inches, 高度 9 Inches 16:9
          prs.slide_height = Inches(height)
          self.width = width
          self.height = height
          blank_slide_layout = prs.slide_layouts[6]  # index 6 是空白slide预设
          slide = prs.slides.add_slide(blank_slide_layout)  # 添加slide
          self.__prs__ = prs
          self.canvas = slide.shapes
          self.background = Background(background_style=background_style, sign=self)
          self.background.draw()
  
      def output(self, dir='.'):
          self.__prs__.save(dir)
  