weasyprint_bytesio.py

from weasyprint import HTML
from io import BytesIO

def convert_html_to_pdf(html_string):
    """ 
    :param html_string: rendered invoice html
    :return: bytes array
    """
    with BytesIO() as byte_io:
        HTML(string=html_string).write_pdf(byte_io)
        return byte_io.getValue()