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Diffstat (limited to 'Doc/whatsnew/2.6.rst')
| -rw-r--r-- | Doc/whatsnew/2.6.rst | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst index 9959ecd..c0ecf01 100644 --- a/Doc/whatsnew/2.6.rst +++ b/Doc/whatsnew/2.6.rst @@ -785,7 +785,7 @@ documentation for a :ref:`complete list <formatstrings>`; here's a sample:: '%' - Percentage. Multiplies the number by 100 and displays in fixed ('f') format, followed by a percent sign. -Classes and types can define a __format__ method to control how they're +Classes and types can define a :meth:`__format__` method to control how they're formatted. It receives a single argument, the format specifier:: def __format__(self, format_spec): @@ -1515,10 +1515,22 @@ Here are all of the changes that Python 2.6 makes to the core Python language. :func:`isnan`, return true if their floating-point argument is infinite or Not A Number. (:issue:`1640`) - The float type has a new instance method :meth:`float.hex` and a - corresponding new class method :meth:`float.fromhex` to convert - floating-point numbers to and from hexadecimal strings, - respectively. (:issue:`3008`) + Conversion functions were added to convert floating-point numbers + into hexadecimal strings. (:issue:`3008`) These functions lets you + convert floats to and from a string representation without + introducing rounding errors from the conversion between decimal and + binary. Floats have a :meth:`hex` method that returns a string + representation, and the ``float.fromhex()`` method converts a string + back into a number:: + + >>> a = 3.75 + >>> a.hex() + '0x1.e000000000000p+1' + >>> float.fromhex('0x1.e000000000000p+1') + 3.75 + >>> b=1./3 + >>> b.hex() + '0x1.5555555555555p-2' * The :mod:`math` module has a number of new functions, and the existing functions have been improved to give more consistent behaviour @@ -1633,6 +1645,12 @@ Optimizations (Original optimization implemented by Armin Rigo, updated for Python 2.6 by Kevin Jacobs; :issue:`1700288`.) +* Function calls that use keyword arguments + are significantly faster thanks to a patch that does a quick pointer + comparison, usually saving the time of a full string comparison. + (Contributed by Raymond Hettinger, after an initial implementation by + Antoine Pitrou; :issue:`1819`.) + * All of the functions in the :mod:`struct` module have been rewritten in C, thanks to work at the Need For Speed sprint. (Contributed by Raymond Hettinger.) |