如何在reportlab python中将文本居中对齐？

from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import Paragraph
from reportlab.lib.enums import TA_CENTER
from reportlab.lib import colors
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

def generate_pdf():
    # 创建PDF画布
    c = canvas.Canvas("center_aligned_text.pdf", pagesize=letter)

    # 设置样式
    styles = getSampleStyleSheet()
    center_aligned_style = styles["Normal"]
    center_aligned_style.alignment = TA_CENTER

    # 创建居中对齐的文本
    text = "这是一段居中对齐的文本"
    centered_text = Paragraph(text, center_aligned_style)

    # 将文本居中绘制在PDF画布上
    centered_text.wrapOn(c, 200, 100)  # 设置文本框的宽度和高度
    centered_text.drawOn(c, 200, 400)  # 设置文本框的位置

    # 保存PDF文件
    c.save()

generate_pdf()