将单个文件附加到电子邮件

Question

请先原谅我。当我尝试研究这个问题时，我最终看到了我根本无法理解的代码。我有大约 3 个小时的 Python 经验，并且尝试的时间可能超出了我的能力范围。

问题很简单。我可以成功地从 R（我的分析软件）调用 Python 来发送电子邮件。添加消息、主题、发往和发自字段是我可以做的。我希望能够发送附件。如果我能只发送一个附件，生活就会很棒。

到目前为止我的代码是

import smtplib
import os
from email.MIMEMultipart import MIMEMultipart
from email.MIMEBase import MIMEBase
from email.MIMEText import MIMEText
from email.Utils import COMMASPACE, formatdate
from email import Encoders
import email.utils

fromaddr = '[email protected]'
toaddrs  = '[email protected]'
msg = MIMEMultipart(MIMEText('This is the body of the e-mail'))
msg['From'] = email.utils.formataddr(('Benjamin Nutter', fromaddr))
msg['To'] = email.utils.formataddr(('Benjamin Nutter', toaddrs))
msg['Subject'] = 'Simple test message'
f = 'filename.pdf'
part=MIMEBase('application', 'octet-stream')
part.set_payload(open(f, 'rb').read())
Encoders.encode_base64(part)
part.add_header('Content-Disposition', 'attachment; filename=\"%s\"' %    os.path.basename(f))
msg.attach(part)

"username = 'user'
"password = 'pw'

server = smtplib.SMTP('smtp.gmail.com:587')
server.ehlo()
server.starttls()
server.ehlo()
server.login(username,password)
server.sendmail(fromaddr, toaddrs, msg.as_string())
server.quit()

当我运行此代码时，我收到消息 预期字符串有效负载：[type 'list']（但使用 < not [）

我今天的自学能力已达到极限。我希望这对于比我更有经验的人来说是一个明显的解决方案。

我希望你们都度过愉快的一天。

Answer 1

您可以尝试使用“邮件程序”，而不是尝试直接使用 SMTP。邮件程序可以在此处找到。

这是一些简单的代码，展示了它是如何工作的。

messages=[]
message = mailer.Message()
message.attach('filename.txt')
message.From = 'Cool guy <[email protected]>'
message.To = 'Random Dude <[email protected]>'
message.Cc = 'Cards Fan <[email protected]>'
message.Subject = 'Test Email'
message.body = 'Here is the body of the email.'
messages.append(message)

emailer = mailer.Mailer(smtphost.example.com)
emailer.send(messages)

我根据当地的一些例子拼凑了这个。上面链接的邮件程序页面还显示了其他示例。找到此代码后，我将所有其他 python 电子邮件代码转换为使用此包。

Answer 2

我知道回答我自己的问题是不好的形式，但它开始奇迹般地工作，没有任何变化。这是一种给我留下第一印象的方式，对吗？

不管怎样，我把它包装成一个 R 函数。这将从 gmail 发送，但我还没有尝试从其他帐户发送。我最感兴趣的是从 Outlook 发送，因为我将使用它从我的脚本中发送分析报告。当我输入雇主的 SMTP 服务器时，出现错误“服务器不支持 SMTP AUTH 扩展”。我怀疑我必须和我的技术支持人员一起解决这个问题。

由于 winDialog() 函数，这可能只适用于 Windows。但这是一个好的开始。

send.email <- function(to, from, subject, 
  message, attachment=NULL,
  username, password,
  server="smtp.gmail.com:587",
  confirmBeforeSend=TRUE){
  # to: a list object of length 1.  Using list("Recipient" = "[email protected]") will send the message to the address but 
  #     the name will appear instead of the address.
  # from: a list object of length 1.  Same behavior as 'to'
  # subject: Character(1) giving the subject line.
  # message: Character(1) giving the body of the message
  # attachment: Character(1) giving the location of the attachment
  # username: character(1) giving the username.  If missing and you are using Windows, R will prompt you for the username.
  # password: character(1) giving the password.  If missing and you are using Windows, R will prompt you for the password.
  # server: character(1) giving the smtp server.
  # confirmBeforeSend: Logical.  If True, a dialog box appears seeking confirmation before sending the e-mail.  This is to 
  #                    prevent me to send multiple updates to a collaborator while I am working interactively.  

  if (!is.list(to) | !is.list(from)) stop("'to' and 'from' must be lists")
  if (length(from) > 1) stop("'from' must have length 1")
  if (length(to) > 1) stop("'send.email' currently only supports one recipient e-mail address")
  if (length(attachment) > 1) stop("'send.email' can currently send only one attachment")
  if (length(message) > 1){ 
    stop("'message' must be of length 1")
    message <- paste(message, collapse="\\n\\n")
  }

  if (is.null(names(to))) names(to) <- to
  if (is.null(names(from))) names(from) <- from
  if (!is.null(attachment)) if (!file.exists(attachment)) stop(paste("'", attachment, "' does not exist!", sep=""))

  if (missing(username)) username <- winDialogString("Please enter your e-mail username", "")
  if (missing(password)) password <- winDialogString("Please enter your e-mail password", "")

  require(rJython)
  rJython <- rJython()

  rJython$exec("import smtplib")
  rJython$exec("import os")
  rJython$exec("from email.MIMEMultipart import MIMEMultipart")
  rJython$exec("from email.MIMEBase import MIMEBase")
  rJython$exec("from email.MIMEText import MIMEText")
  rJython$exec("from email.Utils import COMMASPACE, formatdate")
  rJython$exec("from email import Encoders")
  rJython$exec("import email.utils")

  mail<-c(
  #Email settings
  paste("fromaddr = '", from, "'", sep=""),
  paste("toaddrs  = '", to, "'", sep=""),
  "msg = MIMEMultipart()",
  paste("msg.attach(MIMEText('", message, "'))", sep=""),
  paste("msg['From'] = email.utils.formataddr(('", names(from), "', fromaddr))", sep=""),
  paste("msg['To'] = email.utils.formataddr(('", names(to), "', toaddrs))", sep=""), 
  paste("msg['Subject'] = '", subject, "'", sep=""))

  if (!is.null(attachment)){
    mail <- c(mail,
      paste("f = '", attachment, "'", sep=""),
     "part=MIMEBase('application', 'octet-stream')",
     "part.set_payload(open(f, 'rb').read())",
     "Encoders.encode_base64(part)",
     "part.add_header('Content-Disposition', 'attachment; filename=\"%s\"' % os.path.basename(f))",
     "msg.attach(part)")
  }

#SMTP server credentials
  mail <- c(mail, 
    paste("username = '", username, "'", sep=""),
    paste("password = '", password, "'", sep=""),

#Set SMTP server and send email, e.g., google mail SMTP server
    paste("server = smtplib.SMTP('", server, "')", sep=""),
    "server.ehlo()",
    "server.starttls()",
    "server.ehlo()",
    "server.login(username,password)",
    "server.sendmail(fromaddr, toaddrs, msg.as_string())",
    "server.quit()")

  message.details <- 
    paste("To:               ", names(to), " (", unlist(to), ")", "\n",
          "From:             ", names(from), " (", unlist(from), ")", "\n",
          "Using server:     ", server, "\n",
          "Subject:          ", subject, "\n",
          "With Attachments: ", attachment, "\n",
          "And the message:\n", message, "\n", sep="")

  if (confirmBeforeSend) 
   SEND <- winDialog("yesnocancel", paste("Are you sure you want to send this e-mail to ", unlist(to), "?", sep=""))
   else SEND <- "YES"

  if (SEND %in% "YES"){ 
    jython.exec(rJython,mail)
    cat(message.details)
  }
  else cat("E-mail Delivery was Canceled by the User")
}