Class Generator

Lib/email/generator.py:28–404

Generates output from a Message object tree. This basic generator writes the message to the given file object as plain text.

class Generator:
    """Generates output from a Message object tree.

    This basic generator writes the message to the given file object as plain
    text.
    """
    #
    # Public interface
    #

    def __init__(self, outfp, mangle_from_=None, maxheaderlen=None, *,
                 policy=None):
        """Create the generator for message flattening.

        outfp is the output file-like object for writing the message to.  It
        must have a write() method.

        Optional mangle_from_ is a flag that, when True (the default if policy
        is not set), escapes From_ lines in the body of the message by putting
        a '>' in front of them.

        Optional maxheaderlen specifies the longest length for a non-continued
        header.  When a header line is longer (in characters, with tabs
        expanded to 8 spaces) than maxheaderlen, the header will split as
        defined in the Header class.  Set maxheaderlen to zero to disable
        header wrapping.  The default is 78, as recommended (but not required)
        by RFC 5322 section 2.1.1.

        The policy keyword specifies a policy object that controls a number of
        aspects of the generator's operation.  If no policy is specified,
        the policy associated with the Message object passed to the
        flatten method is used.

        """

        if mangle_from_ is None:
            mangle_from_ = True if policy is None else policy.mangle_from_
        self._fp = outfp
        self._mangle_from_ = mangle_from_
        self.maxheaderlen = maxheaderlen
        self.policy = policy

    def write(self, s):
        # Just delegate to the file object
        self._fp.write(s)

    def flatten(self, msg, unixfrom=False, linesep=None):
        r"""Print the message object tree rooted at msg to the output file
        specified when the Generator instance was created.

        unixfrom is a flag that forces the printing of a Unix From_ delimiter
        before the first object in the message tree.  If the original message
        has no From_ delimiter, a 'standard' one is crafted.  By default, this
        is False to inhibit the printing of any From_ delimiter.

        Note that for subobjects, no From_ line is printed.

        linesep specifies the characters used to indicate a new line in