如何使用 email 模块通过 Python email 发送文件？

Question

I heared, that you can send files per email using the email module. How do I do that?

Answer 1

Take a look at: Here

example from the site

# Import smtplib for the actual sending function
import smtplib

# Here are the email package modules we'll need
from email.mime.image import MIMEImage
from email.mime.multipart import MIMEMultipart

COMMASPACE = ', '

# Create the container (outer) email message.
msg = MIMEMultipart()
msg['Subject'] = 'Our family reunion'
# me == the sender's email address
# family = the list of all recipients' email addresses
msg['From'] = me
msg['To'] = COMMASPACE.join(family)
msg.preamble = 'Our family reunion'

# Assume we know that the image files are all in PNG format
for file in pngfiles:
    # Open the files in binary mode.  Let the MIMEImage class 
    automatically
    # guess the specific image type.
    fp = open(file, 'rb')
    img = MIMEImage(fp.read())
    fp.close()
    msg.attach(img)

# Send the email via our own SMTP server.
s = smtplib.SMTP('localhost')
s.sendmail(me, family, msg.as_string())
s.quit()

Answer 2

Given that you've already created a multipart:

msg = MIMEMultipart()

Then you can add an image by doing:

filename = "..."
with open(filename, "rb") as f:
    attachment = MIMEImage(f.read())

or you can add the string "Hello World" as a test.txt by doing:

filename = "test.txt"
attachment = MIMEText("Hello World")

For binary files or just in general, you can do:

filename = "..."
ctype, encoding = mimetypes.guess_type(filename)
maintype, subtype = ctype.split("/", 1)
attachment = MIMEBase(maintype, subtype)
with open(filename, "rb") as f:
    attachment.set_payload(f.read())
encoders.encode_base64(attachment)

Remember from email import encoders .

At the end you add them to the email by doing:

attachment.add_header("Content-Disposition", "attachment", filename=filename)
msg.attach(attachment)

One important thing to remember, is that all files must be added first. The message must come last in order to conform with RFC 2046 , which dictates:

Receiving user agents should pick and display the last format they are capable of displaying.

Answer 3

You should first know the basics and focus on learning to send a basic email. first, we have built-in module in python 'email' so we use its class 'EmailMessage'

from email.message import EmailMessage

Let's assume you would be using gmail. To send mail you should first enable 'less secure apps' in mail settings, this step is required to be able to send emails from a python script or you get a connection denied error while trying to send email. next, you should import libraries for sending message through SMTP

import smtplib, ssl

email only sends strings through smtp and thus for sending any attachment you must convert it to strings using mimetypes

import mimetypes

also you require os module for processing attachment

import os

To enter password of email service at time of running script and in hidden way use getpass module

import getpass

now, we can create an object for message

message=EmailMessage()

now you should keep in mind, email object is like a dictionary, so go accordingly

message['From']='sender address as string'
message['To']='recipient address as string'
message['Subject']='subject of email as string'

body is little different, if you have one line body it can be just a string otherwise for nice formatting use docstring

body="""Hello!
        World"""
message.set_content(body)

now let's prepare attachment, first we process its path

attachment_path='use absolute path if possible for better implementation'
attachment_filename=os.path.basename(attachment_path)

If MIME type and subtype is not known mimetypes module can be used as:

mime_type, _ = mimetypes.guess_type(attachment_path)

Since we get 'mime_type' as type of mime and subtype separated by '/' we separate them as:

mime_type, mime_subtype=mime_type.split('/', 1)

now we are ready to convert the attachment to a string and attach to the 'message' object

with open(attachment_path, 'rb') as ap:
message.add_attachment(ap.read(), maintype=mime_type, subtype=mime_subtype, filename=attachment_filename)

let's get to sending email:

with smtplib.SMTP("smtp.gmail.com", port=587) as smtp:
  #smtp.set_debuglevel(1) #uncomment this statement to get processing information(run in debug mode)
  smtp.starttls()
  mail_pass=getpass.getpass('Password? ') #uncomment this statement to enter password at time of execution of script
  #default prompt is 'password' for getpass method
  smtp.login(message['From'], mail_pass) #NOTE:here password is in plain context
  #To use password in more secure way, use getpass module
  smtp.send_message(message)

To know if your message sent successfully, let's add

print('message sent successfully from {} to {}'.format(message['From'], message['To']))