Commit Graph

9 Commits

Author SHA1 Message Date
Sergey B Kirpichev 4f3786b761
gh-101773: Optimize creation of Fractions in private methods (#101780)
This PR adds a private `Fraction._from_coprime_ints` classmethod for internal creations of `Fraction` objects, replacing the use of `_normalize=False` in the existing constructor. This speeds up creation of `Fraction` objects arising from calculations. The `_normalize` argument to the `Fraction` constructor has been removed.

Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com>
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
2023-02-27 18:53:22 +00:00
Sergey B Kirpichev 8464b754c4
gh-68163: Correct conversion of Rational instances to float (GH-25619)
* gh-68163: Correct conversion of Rational instances to float

Also document that numerator/denominator properties are instances of Integral.

Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
2022-09-04 13:15:59 +01:00
Raymond Hettinger 4e0ce82058
Revert "bpo-26680: Incorporate is_integer in all built-in and standard library numeric types (GH-6121)" (GH-22584)
This reverts commit 58a7da9e12.
2020-10-07 16:43:44 -07:00
Robert Smallshire 58a7da9e12
bpo-26680: Incorporate is_integer in all built-in and standard library numeric types (GH-6121)
* bpo-26680: Adds support for int.is_integer() for compatibility with float.is_integer().

The int.is_integer() method always returns True.

* bpo-26680: Adds a test to ensure that False.is_integer() and True.is_integer() are always True.

* bpo-26680: Adds Real.is_integer() with a trivial implementation using conversion to int.

This default implementation is intended to reduce the workload for subclass
implementers. It is not robust in the presence of infinities or NaNs and
may have suboptimal performance for other types.

* bpo-26680: Adds Rational.is_integer which returns True if the denominator is one.

This implementation assumes the Rational is represented in it's
lowest form, as required by the class docstring.

* bpo-26680: Adds Integral.is_integer which always returns True.

* bpo-26680: Adds tests for Fraction.is_integer called as an instance method.

The tests for the Rational abstract base class use an unbound
method to sidestep the inability to directly instantiate Rational.
These tests check that everything works correct as an instance method.

* bpo-26680: Updates documentation for Real.is_integer and built-ins int and float.

The call x.is_integer() is now listed in the table of operations
which apply to all numeric types except complex, with a reference
to the full documentation for Real.is_integer().  Mention of
is_integer() has been removed from the section 'Additional Methods
on Float'.

The documentation for Real.is_integer() describes its purpose, and
mentions that it should be overridden for performance reasons, or
to handle special values like NaN.

* bpo-26680: Adds Decimal.is_integer to the Python and C implementations.

The C implementation of Decimal already implements and uses
mpd_isinteger internally, we just expose the existing function to
Python.

The Python implementation uses internal conversion to integer
using to_integral_value().

In both cases, the corresponding context methods are also
implemented.

Tests and documentation are included.

* bpo-26680: Updates the ACKS file.

* bpo-26680: NEWS entries for int, the numeric ABCs and Decimal.

Co-authored-by: Robert Smallshire <rob@sixty-north.com>
2020-10-01 17:30:08 +01:00
Zachary Ware 38c707e7e0 Issue #21741: Update 147 test modules to use test discovery.
I have compared output between pre- and post-patch runs of these tests
to make sure there's nothing missing and nothing broken, on both
Windows and Linux.  The only differences I found were actually tests
that were previously *not* run.
2015-04-13 15:00:43 -05:00
Stefan Krah 1919b7e72b Issue #7652: Integrate the decimal floating point libmpdec library to speed
up the decimal module. Performance gains of the new C implementation are
between 12x and 80x, depending on the application.
2012-03-21 18:25:23 +01:00
Ezio Melotti 4969f709cc #11515: Merge with 3.1. 2011-03-15 05:59:46 +02:00
Mark Dickinson 08ade6faa0 Issue #8188: Comparisons between Decimal objects and other numeric
objects (Fraction, float, complex, int) now all function as expected.
2010-06-11 10:44:52 +00:00
Mark Dickinson dc787d2055 Issue #8188: Introduce a new scheme for computing hashes of numbers
(instances of int, float, complex, decimal.Decimal and
fractions.Fraction) that makes it easy to maintain the invariant that
hash(x) == hash(y) whenever x and y have equal value.
2010-05-23 13:33:13 +00:00