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PEP 457: Better distinguish this PEP from PEP 570 (#920) 

This PEP: shorthand notation to describe positional-only arguments
PEP 570: Elevating that notation to actual Python syntax
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@ -1,5 +1,5 @@
PEP: 457 PEP: 457
Title: Syntax For Positional-Only Parameters Title: Notation For Positional-Only Parameters
Version: $Revision$ Version: $Revision$
Last-Modified: $Date$ Last-Modified: $Date$
Author: Larry Hastings <larry@hastings.org> Author: Larry Hastings <larry@hastings.org>
@ -14,12 +14,18 @@ Created: 08-Oct-2013
Overview Overview
======== ========
This PEP proposes a syntax for positional-only parameters in Python. This PEP proposes a notation for positional-only parameters in Python.
Positional-only parameters are parameters without an externally-usable Positional-only parameters are parameters without an externally-usable
name; when a function accepting positional-only parameters is called, name; when a function accepting positional-only parameters is called,
positional arguments are mapped to these parameters based solely on positional arguments are mapped to these parameters based solely on
their position. their position.
This PEP is an Informational PEP describing the notation for use when
describing APIs that use positional-only parameters (e.g. in Argument
Clinic, or in the string representation of `inspect.Signature`
objects). A separate PEP, PEP 570, proposes elevation of this notation
to full Python syntax.
========= =========
Rationale Rationale
========= =========
@ -41,8 +47,9 @@ positional-only parameters. Put another way, there are
many builtin functions whose signatures are simply not many builtin functions whose signatures are simply not
expressable with Python syntax. expressable with Python syntax.
This PEP proposes a backwards-compatible syntax that should This PEP proposes a notation for such signatures that could form the
permit implementing any builtin in pure Python code. basis of a backwards-compatible syntax that should permit implementing
any builtin in pure Python code (see PEP 570 for that proposal).
----------------------------------------------------- -----------------------------------------------------
Positional-Only Parameter Semantics In Current Python Positional-Only Parameter Semantics In Current Python