\declaremodule{standard}{email.iterators}\modulesynopsis{Iterate over a  message object tree.} Iterating over a message object tree is fairly easy with the\method{Message.walk()} method.  The \module{email.iterators} moduleprovides some useful higher level iterations over message objecttrees. \begin{funcdesc}{body_line_iterator}{msg\optional{, decode}}This iterates over all the payloads in all the subparts of \var{msg},returning the string payloads line-by-line.  It skips over all thesubpart headers, and it skips over any subpart with a payload thatisn't a Python string.  This is somewhat equivalent to reading theflat text representation of the message from a file using\method{readline()}, skipping over all the intervening headers. Optional \var{decode} is passed through to \method{Message.get_payload()}.\end{funcdesc} \begin{funcdesc}{typed_subpart_iterator}{msg\optional{,    maintype\optional{, subtype}}}This iterates over all the subparts of \var{msg}, returning only thosesubparts that match the MIME type specified by \var{maintype} and\var{subtype}. Note that \var{subtype} is optional; if omitted, then subpart MIMEtype matching is done only with the main type.  \var{maintype} isoptional too; it defaults to \mimetype{text}. Thus, by default \function{typed_subpart_iterator()} returns eachsubpart that has a MIME type of \mimetype{text/*}.\end{funcdesc} The following function has been added as a useful debugging tool.  Itshould \emph{not} be considered part of the supported public interfacefor the package. \begin{funcdesc}{_structure}{msg\optional{, fp\optional{, level}}}Prints an indented representation of the content types of themessage object structure.  For example: \begin{verbatim}>>> msg = email.message_from_file(somefile)>>> _structure(msg)multipart/mixed    text/plain    text/plain    multipart/digest        message/rfc822            text/plain        message/rfc822            text/plain        message/rfc822            text/plain        message/rfc822            text/plain        message/rfc822            text/plain    text/plain\end{verbatim} Optional \var{fp} is a file-like object to print the output to.  Itmust be suitable for Python's extended print statement.  \var{level}is used internally.\end{funcdesc}