email
：范例
¶
这里是一些范例对于如何使用
email
包来读写和发送简单 Email 消息，及更复杂的 MIME 消息。
首先，让我们看看如何创建和发送简单文本消息 (文本内容和地址两者可能包含 Unicode 字符)：
# Import smtplib for the actual sending function import smtplib # Import the email modules we'll need from email.message import EmailMessage # Open the plain text file whose name is in textfile for reading. with open(textfile) as fp: # Create a text/plain message msg = EmailMessage() msg.set_content(fp.read()) # me == the sender's email address # you == the recipient's email address msg['Subject'] = f'The contents of {textfile}' msg['From'] = me msg['To'] = you # Send the message via our own SMTP server. s = smtplib.SMTP('localhost') s.send_message(msg) s.quit()
剖析
RFC 822
头可以轻松完成通过使用类从
parser
模块：
# Import the email modules we'll need from email.parser import BytesParser, Parser from email.policy import default # If the e-mail headers are in a file, uncomment these two lines: # with open(messagefile, 'rb') as fp: # headers = BytesParser(policy=default).parse(fp) # Or for parsing headers in a string (this is an uncommon operation), use: headers = Parser(policy=default).parsestr( 'From: Foo Bar <user@example.com>\n' 'To: <someone_else@example.com>\n' 'Subject: Test message\n' '\n' 'Body would go here\n') # Now the header items can be accessed as a dictionary: print('To: {}'.format(headers['to'])) print('From: {}'.format(headers['from'])) print('Subject: {}'.format(headers['subject'])) # You can also access the parts of the addresses: print('Recipient username: {}'.format(headers['to'].addresses[0].username)) print('Sender name: {}'.format(headers['from'].addresses[0].display_name))
这里是如何发送包含一堆可能位于目录下家庭照片的 MIME 消息的范例：
# Import smtplib for the actual sending function. import smtplib # Here are the email package modules we'll need. from email.message import EmailMessage # Create the container email message. msg = EmailMessage() msg['Subject'] = 'Our family reunion' # me == the sender's email address # family = the list of all recipients' email addresses msg['From'] = me msg['To'] = ', '.join(family) msg.preamble = 'You will not see this in a MIME-aware mail reader.\n' # Open the files in binary mode. You can also omit the subtype # if you want MIMEImage to guess it. for file in pngfiles: with open(file, 'rb') as fp: img_data = fp.read() msg.add_attachment(img_data, maintype='image', subtype='png') # Send the email via our own SMTP server. with smtplib.SMTP('localhost') as s: s.send_message(msg)
这里是如何将整个目录下内容作为 Email 消息发送的范例： 1
#!/usr/bin/env python3 """Send the contents of a directory as a MIME message.""" import os import smtplib # For guessing MIME type based on file name extension import mimetypes from argparse import ArgumentParser from email.message import EmailMessage from email.policy import SMTP def main(): parser = ArgumentParser(description="""\ Send the contents of a directory as a MIME message. Unless the -o option is given, the email is sent by forwarding to your local SMTP server, which then does the normal delivery process. Your local machine must be running an SMTP server. """) parser.add_argument('-d', '--directory', help="""Mail the contents of the specified directory, otherwise use the current directory. Only the regular files in the directory are sent, and we don't recurse to subdirectories.""") parser.add_argument('-o', '--output', metavar='FILE', help="""Print the composed message to FILE instead of sending the message to the SMTP server.""") parser.add_argument('-s', '--sender', required=True, help='The value of the From: header (required)') parser.add_argument('-r', '--recipient', required=True, action='append', metavar='RECIPIENT', default=[], dest='recipients', help='A To: header value (at least one required)') args = parser.parse_args() directory = args.directory if not directory: directory = '.' # Create the message msg = EmailMessage() msg['Subject'] = f'Contents of directory {os.path.abspath(directory)}' msg['To'] = ', '.join(args.recipients) msg['From'] = args.sender msg.preamble = 'You will not see this in a MIME-aware mail reader.\n' for filename in os.listdir(directory): path = os.path.join(directory, filename) if not os.path.isfile(path): continue # Guess the content type based on the file's extension. Encoding # will be ignored, although we should check for simple things like # gzip'd or compressed files. ctype, encoding = mimetypes.guess_type(path) if ctype is None or encoding is not None: # No guess could be made, or the file is encoded (compressed), so # use a generic bag-of-bits type. ctype = 'application/octet-stream' maintype, subtype = ctype.split('/', 1) with open(path, 'rb') as fp: msg.add_attachment(fp.read(), maintype=maintype, subtype=subtype, filename=filename) # Now send or store the message if args.output: with open(args.output, 'wb') as fp: fp.write(msg.as_bytes(policy=SMTP)) else: with smtplib.SMTP('localhost') as s: s.send_message(msg) if __name__ == '__main__': main()
这里是如何将像上述范例的 MIME 消息解包到文件目录下的范例：
#!/usr/bin/env python3 """Unpack a MIME message into a directory of files.""" import os import email import mimetypes from email.policy import default from argparse import ArgumentParser def main(): parser = ArgumentParser(description="""\ Unpack a MIME message into a directory of files. """) parser.add_argument('-d', '--directory', required=True, help="""Unpack the MIME message into the named directory, which will be created if it doesn't already exist.""") parser.add_argument('msgfile') args = parser.parse_args() with open(args.msgfile, 'rb') as fp: msg = email.message_from_binary_file(fp, policy=default) try: os.mkdir(args.directory) except FileExistsError: pass counter = 1 for part in msg.walk(): # multipart/* are just containers if part.get_content_maintype() == 'multipart': continue # Applications should really sanitize the given filename so that an # email message can't be used to overwrite important files filename = part.get_filename() if not filename: ext = mimetypes.guess_extension(part.get_content_type()) if not ext: # Use a generic bag-of-bits extension ext = '.bin' filename = f'part-{counter:03d}{ext}' counter += 1 with open(os.path.join(args.directory, filename), 'wb') as fp: fp.write(part.get_payload(decode=True)) if __name__ == '__main__': main()
这里是如何采用替代纯文本版本创建 HTML 消息的范例。为使事情变得更有趣，在 HTML 部分包括相关图像，和将要发送的内容副本保存到磁盘，及发送它。
#!/usr/bin/env python3 import smtplib from email.message import EmailMessage from email.headerregistry import Address from email.utils import make_msgid # Create the base text message. msg = EmailMessage() msg['Subject'] = "Ayons asperges pour le déjeuner" msg['From'] = Address("Pepé Le Pew", "pepe", "example.com") msg['To'] = (Address("Penelope Pussycat", "penelope", "example.com"), Address("Fabrette Pussycat", "fabrette", "example.com")) msg.set_content("""\ Salut! Cela ressemble à un excellent recipie[1] déjeuner. [1] http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718 --Pepé """) # Add the html version. This converts the message into a multipart/alternative # container, with the original text message as the first part and the new html # message as the second part. asparagus_cid = make_msgid() msg.add_alternative("""\ <html> <head></head> <body> <p>Salut!</p> <p>Cela ressemble à un excellent <a href="http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718"> recipie </a> déjeuner. </p> <img src="cid:{asparagus_cid}" /> </body> </html> """.format(asparagus_cid=asparagus_cid[1:-1]), subtype='html') # note that we needed to peel the <> off the msgid for use in the html. # Now add the related image to the html part. with open("roasted-asparagus.jpg", 'rb') as img: msg.get_payload()[1].add_related(img.read(), 'image', 'jpeg', cid=asparagus_cid) # Make a local copy of what we are going to send. with open('outgoing.msg', 'wb') as f: f.write(bytes(msg)) # Send the message via local SMTP server. with smtplib.SMTP('localhost') as s: s.send_message(msg)
若发送来自上一范例的消息，这里是可以处理它的一种方式：
import os import sys import tempfile import mimetypes import webbrowser # Import the email modules we'll need from email import policy from email.parser import BytesParser def magic_html_parser(html_text, partfiles): """Return safety-sanitized html linked to partfiles. Rewrite the href="cid:...." attributes to point to the filenames in partfiles. Though not trivial, this should be possible using html.parser. """ raise NotImplementedError("Add the magic needed") # In a real program you'd get the filename from the arguments. with open('outgoing.msg', 'rb') as fp: msg = BytesParser(policy=policy.default).parse(fp) # Now the header items can be accessed as a dictionary, and any non-ASCII will # be converted to unicode: print('To:', msg['to']) print('From:', msg['from']) print('Subject:', msg['subject']) # If we want to print a preview of the message content, we can extract whatever # the least formatted payload is and print the first three lines. Of course, # if the message has no plain text part printing the first three lines of html # is probably useless, but this is just a conceptual example. simplest = msg.get_body(preferencelist=('plain', 'html')) print() print(''.join(simplest.get_content().splitlines(keepends=True)[:3])) ans = input("View full message?") if ans.lower()[0] == 'n': sys.exit() # We can extract the richest alternative in order to display it: richest = msg.get_body() partfiles = {} if richest['content-type'].maintype == 'text': if richest['content-type'].subtype == 'plain': for line in richest.get_content().splitlines(): print(line) sys.exit() elif richest['content-type'].subtype == 'html': body = richest else: print("Don't know how to display {}".format(richest.get_content_type())) sys.exit() elif richest['content-type'].content_type == 'multipart/related': body = richest.get_body(preferencelist=('html')) for part in richest.iter_attachments(): fn = part.get_filename() if fn: extension = os.path.splitext(part.get_filename())[1] else: extension = mimetypes.guess_extension(part.get_content_type()) with tempfile.NamedTemporaryFile(suffix=extension, delete=False) as f: f.write(part.get_content()) # again strip the <> to go from email form of cid to html form. partfiles[part['content-id'][1:-1]] = f.name else: print("Don't know how to display {}".format(richest.get_content_type())) sys.exit() with tempfile.NamedTemporaryFile(mode='w', delete=False) as f: f.write(magic_html_parser(body.get_content(), partfiles)) webbrowser.open(f.name) os.remove(f.name) for fn in partfiles.values(): os.remove(fn) # Of course, there are lots of email messages that could break this simple # minded program, but it will handle the most common ones.
直到出现提示，上文的输出是：
To: Penelope Pussycat <penelope@example.com>, Fabrette Pussycat <fabrette@example.com> From: Pepé Le Pew <pepe@example.com> Subject: Ayons asperges pour le déjeuner Salut! Cela ressemble à un excellent recipie[1] déjeuner.
脚注
感谢 Matthew Dixon Cowles 的原始灵感和范例。