如何以HTML格式在reportlab PDF中添加隔断线？

from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
from reportlab.lib.colors import black
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import Paragraph, SimpleDocTemplate

def add_divider_line(pdf_canvas):
    pdf_canvas.setStrokeColor(black)
    pdf_canvas.setLineWidth(1)
    pdf_canvas.line(50, pdf_canvas._pagesize[1] - 50, pdf_canvas._pagesize[0] - 50, pdf_canvas._pagesize[1] - 50)

def generate_pdf():
    doc = SimpleDocTemplate("output.pdf", pagesize=letter)
    styles = getSampleStyleSheet()
    elements = []

    # 添加段落
    paragraph = Paragraph("<b>这是一个段落</b>", styles["Normal"])
    elements.append(paragraph)

    # 添加隔断线
    elements.append(Paragraph("<br/><br/>", styles["Normal"]))
    elements.append(Paragraph("<hr/>", styles["Normal"]))
    elements.append(Paragraph("<br/><br/>", styles["Normal"]))

    # 添加另一个段落
    paragraph = Paragraph("<b>这是另一个段落</b>", styles["Normal"])
    elements.append(paragraph)

    # 生成PDF
    doc.build(elements, onFirstPage=add_divider_line, onLaterPages=add_divider_line)

generate_pdf()