bpo-38096: Clean up the "struct sequence" / "named tuple" docs (GH-15895) (GH-15961)
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index 0f2a3a1..84d0fca 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -739,17 +739,28 @@
also :term:`immutable`.
named tuple
- Any tuple-like class whose indexable elements are also accessible using
- named attributes (for example, :func:`time.localtime` returns a
- tuple-like object where the *year* is accessible either with an
- index such as ``t[0]`` or with a named attribute like ``t.tm_year``).
+ The term "named tuple" applies to any type or class that inherits from
+ tuple and whose indexable elements are also accessible using named
+ attributes. The type or class may have other features as well.
- A named tuple can be a built-in type such as :class:`time.struct_time`,
- or it can be created with a regular class definition. A full featured
- named tuple can also be created with the factory function
- :func:`collections.namedtuple`. The latter approach automatically
- provides extra features such as a self-documenting representation like
- ``Employee(name='jones', title='programmer')``.
+ Several built-in types are named tuples, including the values returned
+ by :func:`time.localtime` and :func:`os.stat`. Another example is
+ :data:`sys.float_info`::
+
+ >>> sys.float_info[1] # indexed access
+ 1024
+ >>> sys.float_info.max_exp # named field access
+ 1024
+ >>> isinstance(sys.float_info, tuple) # kind of tuple
+ True
+
+ Some named tuples are built-in types (such as the above examples).
+ Alternatively, a named tuple can be created from a regular class
+ definition that inherits from :class:`tuple` and that defines named
+ fields. Such as class can be written by hand or it can be created with
+ the factory function :func:`collections.namedtuple`. The latter
+ technique also adds some extra methods that may not be found in
+ hand-written or built-in named tuples.
namespace
The place where a variable is stored. Namespaces are implemented as
@@ -1032,14 +1043,6 @@
an :term:`expression` or one of several constructs with a keyword, such
as :keyword:`if`, :keyword:`while` or :keyword:`for`.
- struct sequence
- A tuple with named elements. Struct sequences expose an interface similar
- to :term:`named tuple` in that elements can be accessed either by
- index or as an attribute. However, they do not have any of the named tuple
- methods like :meth:`~collections.somenamedtuple._make` or
- :meth:`~collections.somenamedtuple._asdict`. Examples of struct sequences
- include :data:`sys.float_info` and the return value of :func:`os.stat`.
-
text encoding
A codec which encodes Unicode strings to bytes.