Python SendGrid：如何在HTML邮件内容中正确拼接字符串

你的问题出在没有正确在HTML字符串中解析变量str1，直接写+ str1会被当成普通文本显示，而不是替换成变量的值。下面是几种可行的修复方式：

方法1：使用f-string（推荐，Python3.6+支持） #

在三引号字符串前加f，然后用{str1}作为变量占位符：

str1 = 'StringToBeAdded'
html_content1 = f''' Hi All,
        <br>
        <br>
        Greetings from xyz!
        <br>
        Attached is the report of your data - {str1}
        <br>
        <br>
        Note: This is an automated email. In case of any queries, please reach us at 
        <br>
        Regards,
        <br>
        abc '''
# 修正原代码的语法错误：to_emails和subject的引号要闭合
message = Mail(
    from_email='from@example.com',
    to_emails='to@example.com',
    subject='Mail',
    html_content=html_content1)

方法2：使用str.format()方法 #

把变量位置换成占位符，再调用format传入变量：

str1 = 'StringToBeAdded'
html_content1 = ''' Hi All,
        <br>
        <br>
        Greetings from xyz!
        <br>
        Attached is the report of your data - {}
        <br>
        <br>
        Note: This is an automated email. In case of any queries, please reach us at 
        <br>
        Regards,
        <br>
        abc '''.format(str1)
message = Mail(
    from_email='from@example.com',
    to_emails='to@example.com',
    subject='Mail',
    html_content=html_content1)

方法3：字符串拼接 #

把HTML内容拆分成多段，用+连接变量：

str1 = 'StringToBeAdded'
html_content1 = ''' Hi All,
        <br>
        <br>
        Greetings from xyz!
        <br>
        Attached is the report of your data - ''' + str1 + '''
        <br>
        <br>
        Note: This is an automated email. In case of any queries, please reach us at 
        <br>
        Regards,
        <br>
        abc '''
message = Mail(
    from_email='from@example.com',
    to_emails='to@example.com',
    subject='Mail',
    html_content=html_content1)

另外注意原代码里的两处语法错误：to_emails=to@example.com'少了开头的单引号，subject='Mail,少了结尾的单引号，这些都要修正才能正常运行。

内容的提问来源于stack exchange，提问作者san1