Issue #7117 (backport py3k float repr) continued:
Add sys.float_repr_style attribute ('short' if short float
repr is in used; 'legacy' otherwise).
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 8264a39..5a04f39 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -332,6 +332,18 @@
.. versionadded:: 2.6
+.. data:: float_repr_style
+
+ A string indicating how the :func:`repr` function behaves for
+ floats. If the string has value ``'short'`` then for a finite
+ float ``x``, ``repr(x)`` aims to produce a short string with the
+ property that ``float(repr(x)) == x``. This is the usual behaviour
+ in Python 2.7 and later. Otherwise, ``float_repr_style`` has value
+ ``'legacy'`` and ``repr(x)`` behaves in the same way as it did in
+ versions of Python prior to 2.7.
+
+ .. versionadded:: 2.7
+
.. function:: getcheckinterval()