Python发送包含PDF附件的邮件，使用email.mime.application模块

发送包含PDF附件的邮件是利用Python中的email模块实现的，其中使用email.mime.application模块来创建一个带有附件的邮件。

首先，需要导入相关的模块和类：

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication

然后，需要设置邮件的相关信息，包括发件人、收件人、主题等等：

sender = 'sender@example.com'
receiver = 'receiver@example.com'
subject = 'Email with PDF attachment'

接下来，创建一个带有附件的邮件：

msg = MIMEMultipart()
msg['From'] = sender
msg['To'] = receiver
msg['Subject'] = subject

然后，创建邮件的正文，并将其添加到邮件对象中：

body = 'This email contains a PDF attachment.'
msg.attach(MIMEText(body, 'plain'))

接下来，打开PDF文件，并将其读取为二进制数据：

with open('example.pdf', 'rb') as f:
    pdf_data = f.read()

然后，创建附件对象，并将PDF数据添加到附件对象中：

pdf_attachment = MIMEApplication(pdf_data, Name='example.pdf')
pdf_attachment['Content-Disposition'] = 'attachment; filename="example.pdf"'
msg.attach(pdf_attachment)

最后，使用SMTP服务器发送邮件：

smtp_server = 'smtp.example.com'
username = 'username'
password = 'password'

server = smtplib.SMTP(smtp_server, 587)
server.starttls()
server.login(username, password)
server.send_message(msg)
server.quit()

完整的示例代码如下：

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication

sender = 'sender@example.com'
receiver = 'receiver@example.com'
subject = 'Email with PDF attachment'

msg = MIMEMultipart()
msg['From'] = sender
msg['To'] = receiver
msg['Subject'] = subject

body = 'This email contains a PDF attachment.'
msg.attach(MIMEText(body, 'plain'))

with open('example.pdf', 'rb') as f:
    pdf_data = f.read()

pdf_attachment = MIMEApplication(pdf_data, Name='example.pdf')
pdf_attachment['Content-Disposition'] = 'attachment; filename="example.pdf"'
msg.attach(pdf_attachment)

smtp_server = 'smtp.example.com'
username = 'username'
password = 'password'

server = smtplib.SMTP(smtp_server, 587)
server.starttls()
server.login(username, password)
server.send_message(msg)
server.quit()

注意：在实际使用中，需要将发件人、收件人、SMTP服务器、用户名和密码等信息替换为真实的信息。