we dont support any Python's before 2.3 now.

Lib/email/_compat21.py

-# Copyright (C) 2002 Python Software Foundation
-# Author: barry@zope.com
-
-"""Module containing compatibility functions for Python 2.1.
-"""
-
-from cStringIO import StringIO
-from types import StringType, UnicodeType
-
-False = 0
-True = 1
-
-
-
-# This function will become a method of the Message class
-def walk(self):
-    """Walk over the message tree, yielding each subpart.
-
-    The walk is performed in depth-first order.  This method is a
-    generator.
-    """
-    parts = []
-    parts.append(self)
-    if self.is_multipart():
-        for subpart in self.get_payload():
-            parts.extend(subpart.walk())
-    return parts
-
-
-# Python 2.2 spells floor division //
-def _floordiv(i, j):
-    """Do a floor division, i/j."""
-    return i / j
-
-
-def _isstring(obj):
-    return isinstance(obj, StringType) or isinstance(obj, UnicodeType)
-
-
-
-# These two functions are imported into the Iterators.py interface module.
-# The Python 2.2 version uses generators for efficiency.
-def body_line_iterator(msg, decode=False):
-    """Iterate over the parts, returning string payloads line-by-line.
-
-    Optional decode (default False) is passed through to .get_payload().
-    """
-    lines = []
-    for subpart in msg.walk():
-        payload = subpart.get_payload(decode=decode)
-        if _isstring(payload):
-            for line in StringIO(payload).readlines():
-                lines.append(line)
-    return lines
-
-
-def typed_subpart_iterator(msg, maintype='text', subtype=None):
-    """Iterate over the subparts with a given MIME type.
-
-    Use `maintype' as the main MIME type to match against; this defaults to
-    "text".  Optional `subtype' is the MIME subtype to match against; if
-    omitted, only the main type is matched.
-    """
-    parts = []
-    for subpart in msg.walk():
-        if subpart.get_content_maintype() == maintype:
-            if subtype is None or subpart.get_content_subtype() == subtype:
-                parts.append(subpart)
-    return parts

Lib/email/_compat22.py

-# Copyright (C) 2002 Python Software Foundation
-# Author: barry@zope.com
-
-"""Module containing compatibility functions for Python 2.2.
-"""
-
-from __future__ import generators
-from __future__ import division
-from cStringIO import StringIO
-from types import StringTypes
-
-# Python 2.2.x where x < 1 lacks True/False
-try:
-    True, False
-except NameError:
-    True = 1
-    False = 0
-
-
-
-# This function will become a method of the Message class
-def walk(self):
-    """Walk over the message tree, yielding each subpart.
-
-    The walk is performed in depth-first order.  This method is a
-    generator.
-    """
-    yield self
-    if self.is_multipart():
-        for subpart in self.get_payload():
-            for subsubpart in subpart.walk():
-                yield subsubpart
-
-
-# Python 2.2 spells floor division //
-def _floordiv(i, j):
-    """Do a floor division, i/j."""
-    return i // j
-
-
-def _isstring(obj):
-    return isinstance(obj, StringTypes)
-
-
-
-# These two functions are imported into the Iterators.py interface module.
-# The Python 2.2 version uses generators for efficiency.
-def body_line_iterator(msg, decode=False):
-    """Iterate over the parts, returning string payloads line-by-line.
-
-    Optional decode (default False) is passed through to .get_payload().
-    """
-    for subpart in msg.walk():
-        payload = subpart.get_payload(decode=decode)
-        if _isstring(payload):
-            for line in StringIO(payload):
-                yield line
-
-
-def typed_subpart_iterator(msg, maintype='text', subtype=None):
-    """Iterate over the subparts with a given MIME type.
-
-    Use `maintype' as the main MIME type to match against; this defaults to
-    "text".  Optional `subtype' is the MIME subtype to match against; if
-    omitted, only the main type is matched.
-    """
-    for subpart in msg.walk():
-        if subpart.get_content_maintype() == maintype:
-            if subtype is None or subpart.get_content_subtype() == subtype:
-                yield subpart