Simplify and shorten abi_features rationale

Author: zklaus

peps/pep-0780.rst

@@ -104,21 +104,13 @@ extension to include the new environment marker.
 Adding ``sys.abi_features`` to the Python Standard Library
 ----------------------------------------------------------
 
-The Python standard library already has one mechanism to provide information
-about the ABI of the interpreter, namely the ``sys.abiflags`` attribute.
-This attribute is a string that contains a number of flags, such as ``d`` for
-debug builds, but it is not easily understood and not uniformly available.
-The new ``sys.abi_features`` attribute is both and is designed to be a superset
-of the information contained in ``sys.abiflags``, which is why we chose to
-include the ``debug`` feature.
-The established ``sys.abiflags`` also has a direct link to the naming of
-various filesystem paths. This can be convenient, but precludes its use for the
-documentation of important ABI features that are *not* intended to impact these
-paths.
-
-The new ``sys.abi_features`` attribute provides a place for this, and because
-it decouples the information from filesystem paths, it can offer significantly
-more clarity.
+The Python standard library already has mechanisms to provide information about
+the ABI of the interpreter, like the :data:`!sys.abiflags` attribute and the
+:mod:`sysconfig` module, but these do not provide all the `ABI Features`_ that
+are relevant for environment markers.
+The new attribute :data:`!sys.abi_features` is a natural extension to the
+existing mechanisms, and it is a simple and intuitive way to provide this
+information, including the information from :data:`!sys.abiflags`.
 
 A Forward Looking View on Free-Threaded Python
 ----------------------------------------------
@@ -229,8 +221,8 @@ All Python interpreters MUST provide the ``sys.abi_features`` attribute as a
 ``frozenset`` of strings, which MUST contain only the `ABI Features`_ that are
 defined in this PEP or in a subsequent PEP.
 
-An example value would be ``sys.abi_features == {"free-threading",
-"debug", "32-bit"}`` on a free-threaded debug build for win32.
+An example value would be ``sys.abi_features == frozenset({"free-threading",
+"debug", "32-bit"})`` on a free-threaded debug build for win32.
 
 Environment Markers
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