Internet Data Handling » mailbox

[dieter]

Adam Jensen <hanzer at riseup.net> writes:
> ...
> https://docs.python.org/2.7/library/mailbox.html#examples
>
> import mailbox
> for message in mailbox.mbox('~/mbox'):
>     subject = message['subject']       # Could possibly be None.
>     if subject and 'python' in subject.lower():
>         print subject
>
> What is the structure of "message"? I guess it's a dictionary but what
> is its structure? What are the keys?

In addition to the previous (excellent) responses:

A "message" models a MIME (RFC1521 Multipurpose Internet Mail Extensions)
message (the international standard for the structure of emails).
The standard tells you that a message consists essentially of two
parts: a set of headers and a body and describes standard headers
and their intended meaning (e.g. "To", "From", "Subject", ...).
It allows a message to contain non-standard headers as well.

With this knowledge, your "keys" related question can be answered:
there is a (case insensitive) key for each header actually present
in your message. If the message contains several headers with
the same name, the subscription access gives you the first one;
there is an alternative method to access all of them.