# the code that depicts issuse posted on StackOverflow
# http://stackoverflow.com/questions/23599457/how-to-parse-an-email-in-python-without-closing-the-file

from email.parser import BytesParser, Parser
from io import StringIO, TextIOWrapper

f = open('mail.eml', 'r') #change to 'rb' for BytesParser

def parsefromfile(f, headersonly=None):
    info_msg = "Type of f is now: {}, the id is: {}."
    f.seek(0)
    msg = Parser().parse(f,headersonly) #BytesParser make the code fail on the next f.seek
    print(msg)
    print(msg.get('date', None))
    f.seek(0)
    print(f.read())

parsefromfile(f)