我在python中使用pdfkit从html文件生成PDF，但生成的PDF只显示零（0）。下面是代码。

from jinja2 import Environment, FileSystemLoader
import pdfkit

template_loader = FileSystemLoader('.')
temp_env = Environment(loader=template_loader)

template = temp_env.get_template("sample-template.html")
output = template.render(curse = "CSE")

with open('result.html', 'w') as f:
    f.write(output)

wkpath = "C:/Program Files/wkhtmltopdf/bin/wkhtmltopdf.exe"
config = pdfkit.configuration(wkhtmltopdf=wkpath)
pdfkit.from_file('result.html', 'output' + '.pdf',  options={"enable-local-file-access": ""},
                 configuration=config)

Output PDF
wkhtmltopdf已安装。