Tying it all together

Let us tie this chapter together with a more complex example. The following is the code for the EmailAction class. This action sends an e-mail to the user when the rule is matched.

import smtplib
from email.mime.text import MIMEText

class EmailAction:
    """Send an email when a rule is matched"""
    from_email = "[email protected]"

    def __init__(self, to):
        self.to_email = to

    def execute(self, content):
        message = MIMEText(content)
        message["Subject"] = "New Stock Alert"
        message["From"] = "[email protected]"
        message["To"] = self.to_email
        smtp = smtplib.SMTP("email.stocks.com")
        try:
            smtp.send_message(message)
        finally:
            smtp.quit()

The following is how the library works:

1. We instantiate the SMTP class in the smtplib library, passing it the server we want to connect to. This returns the SMTP object.

2. We call the send_message method on the SMTP object, passing in the e-mail message...