1 # Copyright (C) 2001-2006 Python Software Foundation

     2 # Author: Barry Warsaw

     3 # Contact: email-sig@python.org

     4 

     5 """Various types of useful iterators and generators."""

     6 

     7 __all__ = [

     8     'body_line_iterator',

     9     'typed_subpart_iterator',

    10     'walk',

    11     # Do not include _structure() since it's part of the debugging API.

    12     ]

    13 

    14 import sys

    15 from cStringIO import StringIO

    16 

    17 

    18 

    19 # This function will become a method of the Message class

    20 def walk(self):

    21     """Walk over the message tree, yielding each subpart.

    22 

    23     The walk is performed in depth-first order.  This method is a

    24     generator.

    25     """

    26     yield self

    27     if self.is_multipart():

    28         for subpart in self.get_payload():

    29             for subsubpart in subpart.walk():

    30                 yield subsubpart

    31 

    32 

    33 

    34 # These two functions are imported into the Iterators.py interface module.

    35 def body_line_iterator(msg, decode=False):

    36     """Iterate over the parts, returning string payloads line-by-line.

    37 

    38     Optional decode (default False) is passed through to .get_payload().

    39     """

    40     for subpart in msg.walk():

    41         payload = subpart.get_payload(decode=decode)

    42         if isinstance(payload, basestring):

    43             for line in StringIO(payload):

    44                 yield line

    45 

    46 

    47 def typed_subpart_iterator(msg, maintype='text', subtype=None):

    48     """Iterate over the subparts with a given MIME type.

    49 

    50     Use `maintype' as the main MIME type to match against; this defaults to

    51     "text".  Optional `subtype' is the MIME subtype to match against; if

    52     omitted, only the main type is matched.

    53     """

    54     for subpart in msg.walk():

    55         if subpart.get_content_maintype() == maintype:

    56             if subtype is None or subpart.get_content_subtype() == subtype:

    57                 yield subpart

    58 

    59 

    60 

    61 def _structure(msg, fp=None, level=0, include_default=False):

    62     """A handy debugging aid"""

    63     if fp is None:

    64         fp = sys.stdout

    65     tab = ' ' * (level * 4)

    66     print >> fp, tab + msg.get_content_type(),

    67     if include_default:

    68         print >> fp, '[%s]' % msg.get_default_type()

    69     else:

    70         print >> fp

    71     if msg.is_multipart():

    72         for subpart in msg.get_payload():

    73             _structure(subpart, fp, level+1, include_default)