o_18ufhmfmq19t513t3lgmn5l1qa8a.pdf

CHAPTER 10 ■ BATTERIES INCLUDED 245
User-Agent: Microsoft-Outlook-Express-Macintosh-Edition/5.02.2022
Date: Wed, 19 Dec 2004 17:22:42 -0700
Subject: Re: Spam
From: Foo Fie
To: Magnus Lie Hetland
CC:
Message-ID:
In-Reply-To:
Mime-version: 1.0
Content-type: text/plain; charset="US-ASCII"
Content-transfer-encoding: 7bit
Status: RO
Content-Length: 55
Lines: 6
So long, and thanks for all the spam!
Yours,
Foo Fie
Let’s try to find out who this e-mail is from. If you examine the text, I’m sure you can figure it out in this case (especially
if you look at the message itself, at the bottom, of course). But can you see a general pattern? How do you extract
the name of the sender, without the e-mail address? Or, how can you list all the e-mail addresses mentioned in the
headers? Let’s handle the first task first.
The line containing the sender begins with the string 'From: ' and ends with an e-mail address enclosed in angle
brackets (< and >). You want the text found between those. If you use the fileinput module, this ought to be an
easy task. A program solving the problem is shown in Listing 10-10.
■Note You could solve this problem without using regular expressions if you wanted. You could also use
the email module.
Listing 10-10. A Program for Finding the Sender of an E-mail
# find_sender.py
import fileinput, re
pat = re.compile('From: (.*?) $')
for line in fileinput.input():
m = pat.match(line)
if m: print m.group(1)
You can then run the program like this (assuming that the e-mail message is in the text file message.eml):