Unable to parse email (.msg) in python 3.6 - email

Question

I have set of .msg files stored in E:/ drive that I have to read and extract some information from it. For that i am using the below code in Python 3.6
from email.parser import Parser
p = Parser()
headers = p.parse(open('E:/Ratan/msg_files/Test1.msg', encoding='Latin-1'))
print('To: %s' % headers['To'])
print('From: %s' % headers['From'])
print('Subject: %s' % headers['subject'])
In the output I am getting as below.
To: None
From: None
Subject: None
I am not getting the actual values in To, FROM and subject fields.
Any thoughts why it is not printing the actual values?
Please download my sample msg file from this link:
drive.google.com/file/d/1pwWWG3BgsMKwRr0WmP8GqzG3WX4GmEy6/vi‌​ew

Answer 1

Here is a demonstration of how to use some of python's standard email libraries.
You didn't show us your input file in the question, and the g-drive URL is a deadlink.
The code below looks just like yours and works fine, so I don't know what is odd about your environment, modulo some Windows 'rb' binary open nonsense, CRLFs, or the Latin1 encoding.
I threw in .upper() but it does nothing beyond showing that the API is case insensitive.
#! /usr/bin/env python3
from email.parser import Parser
from pathlib import Path
import mailbox
def extract_messages(maildir, mbox_file, k=2, verbose=False):
for n, message in enumerate(mailbox.mbox(mbox_file)):
with open(maildir / f'{n}.txt', 'w') as fout:
fout.write(str(message))
hdrs = 'From Date Subject In-Reply-To References Message-ID'.split()
p = Parser()
for i in range(min(k, n)):
with open(maildir / f'{i}.txt') as fin:
msg = p.parse(fin)
print([len(msg[hdr.upper()] or '')
for hdr in hdrs])
for k, v in msg.items():
print(k, v)
print('')
if verbose:
print(msg.get_payload())
if __name__ == '__main__':
# from https://mail.python.org/pipermail/python-dev/
maildir = Path('/tmp/py-dev/')
extract_messages(maildir, maildir / '2018-January.txt')