python html EmailMessage 奇怪的字符

Question

我正在基于模板文件生成 email。 加载 HTML 时，格式没问题，只要我将其加载到 msg object 中，就会添加一些奇怪的字符。

    try: 
        with open(f'{SCRIPT_ASSET_PATH}email_template_{args.lang}.txt') as f:
            html_data=f.read().replace("templateCustomer",args.customer).replace("templateCode",str(demo_code)).replace("templateFullName",USER_FULLNAME).replace("templateBusinessTitle",USER_BUSINESS_TITLE).replace("templateImage",'<img src="cid:{image_cid}"></img>'.format(image_cid=image_cid[1:-1]))
    except FileNotFoundError: 
        print_fail(f"ERROR loading email template, WILL NOT prepare email. Check if email_template_{args.lang}.txt is in assets folder")
        return False
    print(html_data) # here it is fine
    msg = EmailMessage()
    msg['Subject'] = "Demo access"
    msg['From'] = settings["userEmail"]
    msg['To'] = "fillin@customerdomain.com"
    msg.make_alternative() 
    msg.add_alternative(html_data, subtype='html') # something happens here

在msg._payload中现在添加了一些随机字符（普通字母、等号等），例如"3D" : href=3D"www.mylink.com"

为什么会这样？ 它似乎与我需要专门编码的 HTML 特定字符无关。 在示例中，将“list=d”添加到不包含特殊字符的简单字符串“products”中：

您现在可以使用下面列出的产品试用该用例。

变成

您现在可以尝试使用下面列出的产品的用例。

Answer 1

找到处理这个问题的正确方法真的很棘手。 周围也有很多答案，但是一旦修复了某些问题，就会出现其他问题（图像嵌入不起作用，超链接有问题等）

我现在设法通过以下方式解决它：

cid=str(uuid.uuid4())
    try: 
        with open(f'{SCRIPT_ASSET_PATH}email_template_{args.lang}.txt') as f:
            html_data=f.read().replace("templateImage",'<img src="cid:{image_cid}"></img>'.format(image_cid=cid))
            html_data = html_data.encode("ascii", "xmlcharrefreplace") # this repairs any broken special characters in the mail

    except FileNotFoundError: 
        print_fail(f"ERROR loading email template, WILL NOT prepare email. Check if email_template_{args.lang}.txt is in scriptfolder")
        return False

    msg = MIMEMultipart('related') # nearly every other post pointed me to "alternative" but alternative broke the image embedding
    msg['Subject'] = "Demo access"
    msg['From'] = settings["userEmail"]
    msg['To'] = "fillin@customerdomain.com"
    text = "Automatic demo email did not work as expected, please contact us."


    outfile_name = f"{assets_path}email_template.eml"
    part1 = MIMEText(text, 'plain')
    part2 = MIMEText(html_data, 'html', 'utf-8')
    msg.attach(part1)
    msg.attach(part2)
    with open(f'{assets_path}merged.jpg', 'rb') as img:
        mime = MIMEBase('image', 'jpg', filename='merged.jpg')
        mime.add_header('Content-Disposition', 'attachment', filename='merged.jpg')
        mime.add_header('X-Attachment-Id', cid)
        mime.add_header('Content-ID', f'<{cid}>')
        mime.set_payload(img.read())
        encoders.encode_base64(mime)
        msg.attach(mime)

    with open(outfile_name, 'w') as outfile:
        gen = Generator(outfile)
        gen.flatten(msg=msg)