Lib/email/_compat21.py

   1 # Copyright (C) 2002 Python Software Foundation
   2 # Author: barry@zope.com
   3
   4 """Module containing compatibility functions for Python 2.1.
   5 """
   6
   7 from cStringIO import StringIO
   8 from types import StringType, UnicodeType
   9
  10
  11 \f
  12 # This function will become a method of the Message class
  13 def walk(self):
  14     """Walk over the message tree, yielding each subpart.
  15
  16     The walk is performed in depth-first order.  This method is a
  17     generator.
  18     """
  19     parts = []
  20     parts.append(self)
  21     if self.is_multipart():
  22         for subpart in self.get_payload():
  23             parts.extend(subpart.walk())
  24     return parts
  25
  26
  27 # Python 2.2 spells floor division //
  28 def _floordiv(i, j):
  29     """Do a floor division, i/j."""
  30     return i / j
  31
  32
  33 def _isstring(obj):
  34     return isinstance(obj, StringType) or isinstance(obj, UnicodeType)
  35
  36
  37 \f
  38 # These two functions are imported into the Iterators.py interface module.
  39 # The Python 2.2 version uses generators for efficiency.
  40 def body_line_iterator(msg):
  41     """Iterate over the parts, returning string payloads line-by-line."""
  42     lines = []
  43     for subpart in msg.walk():
  44         payload = subpart.get_payload()
  45         if _isstring(payload):
  46             for line in StringIO(payload).readlines():
  47                 lines.append(line)
  48     return lines
  49
  50
  51 def typed_subpart_iterator(msg, maintype='text', subtype=None):
  52     """Iterate over the subparts with a given MIME type.
  53
  54     Use `maintype' as the main MIME type to match against; this defaults to
  55     "text".  Optional `subtype' is the MIME subtype to match against; if
  56     omitted, only the main type is matched.
  57     """
  58     parts = []
  59     for subpart in msg.walk():
  60         if subpart.get_main_type('text') == maintype:
  61             if subtype is None or subpart.get_subtype('plain') == subtype:
  62                 parts.append(subpart)
  63     return parts