From 98b140c19620eae8e6e44d9edc7ab02aaeaa4031 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Sun, 23 Jan 2011 21:05:46 +0000 Subject: Add entry for reprlib. --- Doc/library/reprlib.rst | 3 +++ Doc/whatsnew/3.2.rst | 29 ++++++++++++++++++++++++++--- Lib/reprlib.py | 1 + 3 files changed, 30 insertions(+), 3 deletions(-) diff --git a/Doc/library/reprlib.rst b/Doc/library/reprlib.rst index c794a8d..0e870da 100644 --- a/Doc/library/reprlib.rst +++ b/Doc/library/reprlib.rst @@ -5,6 +5,9 @@ :synopsis: Alternate repr() implementation with size limits. .. sectionauthor:: Fred L. Drake, Jr. +**Source code:** :source:`Lib/reprlib.py` + +-------------- The :mod:`reprlib` module provides a means for producing object representations with limits on the size of the resulting strings. This is used in the Python diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst index 3c1da9f..c680d31 100644 --- a/Doc/whatsnew/3.2.rst +++ b/Doc/whatsnew/3.2.rst @@ -987,6 +987,32 @@ implemented:: (Patch submitted by Daniel Urban; :issue:`5867`.) +reprlib +------- + +When writing a :meth:`__repr__` method for a custom container, it is easy to +forget to handle the case where a member refers back to the container itself. +Python's builtin objects such as :class:`list` and :class:`set` handle +self-reference by displaying "..." in the recursive part of the representation +string. + +To help write such :meth:`__repr__` methods, the :mod:`reprlib` module has a new +decorator, :func:`reprlib.recursive_repr`, for detecting recursive calls to +:meth:`__repr__` and substituting a placeholder string instead: + + >>> class MyList(list): + @recursive_repr() + def __repr__(self): + return '<' + '|'.join(map(repr, self)) + '>' + + >>> m = MyList('abc') + >>> m.append(m) + >>> m.append('x') + >>> print(m) + <'a'|'b'|'c'|...|'x'> + +(Contributed by Raymond Hettinger.) + contextlib ---------- @@ -1697,9 +1723,6 @@ reading directly from dictionaries and strings. - non-UTF8 percent encoding of non-ASCII characters Issue 2987 for IPv6 (RFC2732) support in urlparse -.. XXX reprlib.recursive_repr - - Multi-threading =============== diff --git a/Lib/reprlib.py b/Lib/reprlib.py index 7b5c436..9fee304 100644 --- a/Lib/reprlib.py +++ b/Lib/reprlib.py @@ -30,6 +30,7 @@ def recursive_repr(fillvalue='...'): wrapper.__module__ = getattr(user_function, '__module__') wrapper.__doc__ = getattr(user_function, '__doc__') wrapper.__name__ = getattr(user_function, '__name__') + wrapper.__name__ = getattr(user_function, '__annotations__', {}) return wrapper return decorating_function -- cgit v0.12