Lib/email/_compat22.py

   1 # Copyright (C) 2002 Python Software Foundation
   2 # Author: barry@zope.com
   3
   4 """Module containing compatibility functions for Python 2.2.
   5 """
   6
   7 from __future__ import generators
   8 from __future__ import division
   9 from cStringIO import StringIO
  10 from types import StringTypes
  11
  12 # Python 2.2.x where x < 1 lacks True/False
  13 try:
  14     True, False
  15 except NameError:
  16     True = 1
  17     False = 0
  18
  19
  20 \f
  21 # This function will become a method of the Message class
  22 def walk(self):
  23     """Walk over the message tree, yielding each subpart.
  24
  25     The walk is performed in depth-first order.  This method is a
  26     generator.
  27     """
  28     yield self
  29     if self.is_multipart():
  30         for subpart in self.get_payload():
  31             for subsubpart in subpart.walk():
  32                 yield subsubpart
  33
  34
  35 # Python 2.2 spells floor division //
  36 def _floordiv(i, j):
  37     """Do a floor division, i/j."""
  38     return i // j
  39
  40
  41 def _isstring(obj):
  42     return isinstance(obj, StringTypes)
  43
  44
  45 \f
  46 # These two functions are imported into the Iterators.py interface module.
  47 # The Python 2.2 version uses generators for efficiency.
  48 def body_line_iterator(msg, decode=False):
  49     """Iterate over the parts, returning string payloads line-by-line.
  50
  51     Optional decode (default False) is passed through to .get_payload().
  52     """
  53     for subpart in msg.walk():
  54         payload = subpart.get_payload(decode=decode)
  55         if _isstring(payload):
  56             for line in StringIO(payload):
  57                 yield line
  58
  59
  60 def typed_subpart_iterator(msg, maintype='text', subtype=None):
  61     """Iterate over the subparts with a given MIME type.
  62
  63     Use `maintype' as the main MIME type to match against; this defaults to
  64     "text".  Optional `subtype' is the MIME subtype to match against; if
  65     omitted, only the main type is matched.
  66     """
  67     for subpart in msg.walk():
  68         if subpart.get_content_maintype() == maintype:
  69             if subtype is None or subpart.get_content_subtype() == subtype:
  70                 yield subpart