python 中的 smtplib.server.sendmail 函数引发 UnicodeEncodeError: 'ascii' codec can't encode character

Question

我正在尝试编辑一个文本文件，然后使用 python 脚本将其作为电子邮件正文发送，但我收到了 unicode 编码错误。经过一番研究，我发现解决方案是使用 .encode('utf-8') 方法，但这对我不起作用，因为 sendmail() 方法只发送字符串

这是我使用的python代码片段：

irtem = open('irtemplate.txt')
data = irtem.read().replace('(name)', eng_name).replace('(customer)', 
cu_name).replace('(sr)', SR_num).replace('(problem)', 
prob_description).replace('(email)', eng_email).replace('(details)', 
details_req).replace('(tele)', eng_tele)


message_text = data
message = "From: %s\r\n" % fromaddr + "To: %s\r\n" % toaddr + "CC: 
%s\r\n" % ",".join(cc) + "Subject: %s\r\n" % message_subject + "\r\n" + 
message_text
toaddrs = [toaddr] + cc + bcc
server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, message)
server.quit()

追溯：

Traceback (most recent call last):
File "autoIR.py", line 39, in <module>
server.sendmail(fromaddr, toaddrs, message)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/smtplib.py", line 855, in sendmail
msg = _fix_eols(msg).encode('ascii')
UnicodeEncodeError: 'ascii' codec can't encode character '\u2019' in 
position 168: ordinal not in range(128)

Answer 1

smtplib.server的sendmail方法需要一个bytes实例；如果它得到 astr它会尝试将其编码为 ASCII，UnicodeEncodeError如果str包含任何非 ASCII 字符，则会产生 a 。

您可以通过自己编码消息来解决此问题：

>>> msg = 'Hello Wørld'
>>> from_ = 'a@example.com'
>>> to_ = 'b@example.com'
>>> subject = 'Hello'

>>> fmt = 'From: {}\r\nTo: {}\r\nSubject: {}\r\n{}'

>>> server.sendmail(to_, from_, fmt.format(to_, from_, subject, msg).encode('utf-8'))
{}

这将发送此消息*：

b'From: b@example.com'
b'To: a@example.com'
b'Subject: Hello'
b'Hello W\xc3\xb8rld'

但是，如果您想随消息发送非文本二进制数据，则此解决方法将不起作用。

更好的解决方案是使用电子邮件包中的EmailMessage类。

>>> from email.message import EmailMessage
>>> em = EmailMessage()
>>> em.set_content(msg)
>>> em['To'] = to_
>>> em['From'] = from_
>>> em['Subject'] = subject

>>> # NB call the server's *send_message* method
>>> server.send_message(em)
{}

这会发送此消息；请注意告诉收件人使用的编码的额外标头：

>>> msg = 'Hello Wørld'
>>> from_ = 'a@example.com'
>>> to_ = 'b@example.com'
>>> subject = 'Hello'

>>> fmt = 'From: {}\r\nTo: {}\r\nSubject: {}\r\n{}'

>>> server.sendmail(to_, from_, fmt.format(to_, from_, subject, msg).encode('utf-8'))
{}

*python -m smtpd -n -c DebuggingServer localhost:1025在单独的终端中运行该命令以捕获消息数据。