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Diffstat (limited to 'Doc/library/reprlib.rst')
| -rw-r--r-- | Doc/library/reprlib.rst | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/Doc/library/reprlib.rst b/Doc/library/reprlib.rst index 958ead6..0e870da 100644 --- a/Doc/library/reprlib.rst +++ b/Doc/library/reprlib.rst @@ -1,11 +1,13 @@ :mod:`reprlib` --- Alternate :func:`repr` implementation ======================================================== - .. module:: reprlib :synopsis: Alternate repr() implementation with size limits. .. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org> +**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 @@ -35,6 +37,29 @@ This module provides a class, an instance, and a function: similar to that returned by the built-in function of the same name, but with limits on most sizes. +In addition to size-limiting tools, the module also provides a decorator for +detecting recursive calls to :meth:`__repr__` and substituting a placeholder +string instead. + +.. decorator:: recursive_repr(fillvalue="...") + + Decorator for :meth:`__repr__` methods to detect recursive calls within the + same thread. If a recursive call is made, the *fillvalue* is returned, + otherwise, the usual :meth:`__repr__` call is made. For example: + + >>> 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'> + + .. versionadded:: 3.2 + .. _repr-objects: |