Add more namedtuple() test cases. Neaten the code and comments.

1 files changed, 11 insertions, 10 deletions

diff --git a/Lib/collections.py b/Lib/collections.py
index be4d4fd..a43fdfa 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -1,4 +1,9 @@
 __all__ = ['deque', 'defaultdict', 'namedtuple']
+# For bootstrapping reasons, the collection ABCs are defined in _abcoll.py.
+# They should however be considered an integral part of collections.py.
+from _abcoll import *
+import _abcoll
+__all__ += _abcoll.__all__
 
 from _collections import deque, defaultdict
 from operator import itemgetter as _itemgetter
@@ -6,12 +11,6 @@ from itertools import izip as _izip
 from keyword import iskeyword as _iskeyword
 import sys as _sys
 
-# For bootstrapping reasons, the collection ABCs are defined in _abcoll.py.
-# They should however be considered an integral part of collections.py.
-from _abcoll import *
-import _abcoll
-__all__ += _abcoll.__all__
-
 def namedtuple(typename, field_names, verbose=False):
     """Returns a new subclass of tuple with named fields.
 
@@ -19,9 +18,9 @@ def namedtuple(typename, field_names, verbose=False):
     >>> Point.__doc__                   # docstring for the new class
     'Point(x, y)'
     >>> p = Point(11, y=22)             # instantiate with positional args or keywords
-    >>> p[0] + p[1]                     # works just like the tuple (11, 22)
+    >>> p[0] + p[1]                     # indexable like a plain tuple:  (11, 22)
     33
-    >>> x, y = p                        # unpacks just like a tuple
+    >>> x, y = p                        # unpack like a regular tuple
     >>> x, y
     (11, 22)
     >>> p.x + p.y                       # fields also accessable by name
@@ -61,7 +60,6 @@ def namedtuple(typename, field_names, verbose=False):
     template = '''class %(typename)s(tuple):
         '%(typename)s(%(argtxt)s)' \n
         __slots__ = () \n
-        _fields = property(lambda self: %(field_names)r) \n
         def __new__(cls, %(argtxt)s):
             return tuple.__new__(cls, (%(argtxt)s)) \n
         def __repr__(self):
@@ -71,7 +69,10 @@ def namedtuple(typename, field_names, verbose=False):
             return dict(zip(%(field_names)r, self)) \n
         def _replace(self, **kwds):
             'Return a new %(typename)s object replacing specified fields with new values'
-            return %(typename)s(*map(kwds.get, %(field_names)r, self)) \n\n''' % locals()
+            return %(typename)s(*map(kwds.get, %(field_names)r, self)) \n
+        @property
+        def _fields(self):
+            return %(field_names)r \n\n''' % locals()
     for i, name in enumerate(field_names):
         template += '        %s = property(itemgetter(%d))\n' % (name, i)
     if verbose: