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Elaborate on the calculation used in the random module.

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Raymond Hettinger 2010-12-15 19:33:49 +00:00
parent 67f0b6c5f2
commit 99db3fd03b
1 changed files with 24 additions and 22 deletions
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Doc/whatsnew/3.2.rst
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@ -515,18 +515,18 @@ Some smaller changes made to the core Python language are:
New, Improved, and Deprecated Modules
=====================================
Python's standard library is now receiving significant maintenance efforts
and quality improvements.
Python's standard library has undergone significant maintenance efforts and
quality improvements.
The biggest news for Python 3.2 is that the :mod:`email` package and
:mod:`nntplib` modules now work correctly with Python 3.2's bytes/text model.
:mod:`nntplib` modules now work correctly with the bytes/text model in Python 3.
For the first time, there is correct handling of inputs with mixed encodings.
Another significant win is the addition of substantially better support for
*SSL* connections and security certificates.
In addition, many more functions and classes now have a :term:`context manager`
to support convenient and reliable resource clean-up using the
In addition, more functions and classes now have a :term:`context manager` to
support convenient and reliable resource clean-up using the
:keyword:`with`-statement.
email
@ -930,10 +930,13 @@ random
------
The integer methods in the :mod:`random` module now do a better job of producing
uniform distributions. Previously, they used ``int(n*random())`` which had a
slight bias whenever *n* was not a power of two. The functions and methods
affected are :func:`~random.randrange`, :func:`~random.randint`,
:func:`~random.choice`, :func:`~random.shuffle` and :func:`~random.sample`.
uniform distributions. Previously, they computed selections with
``int(n*random())`` which had a slight bias whenever *n* was not a power of two.
Now, multiple selections are made from a range upto the next power of two and a
selection is kept only when it falls within the range ``0 <= x < n``. The
functions and methods affected are :func:`~random.randrange`,
:func:`~random.randint`, :func:`~random.choice`, :func:`~random.shuffle` and
:func:`~random.sample`.
(Contributed by Raymond Hettinger; :issue:`9025`.)
@ -1057,21 +1060,20 @@ pdb
The :mod:`pdb` debugger module gained a number of usability improvements:
- :file:`pdb.py` now has a ``-c`` option that executes commands as given in a
:file:`.pdbrc` script file.
- A :file:`.pdbrc` script file can contain ``continue`` and ``next`` commands
that continue debugging.
- The :class:`Pdb` class constructor now accepts a *nosigint* argument.
- new commands: ``l(list)``, ``ll(long list`` and ``source`` for
listing source code.
- new commands: ``display`` and ``undisplay`` for showing or hiding
the value of an expression if it has changed.
- new command: ``interact`` for starting an interactive interpreter containing
the global and local names found in the current scope.
- breakpoints can be cleared by breakpoint number
* :file:`pdb.py` now has a ``-c`` option that executes commands as given in a
:file:`.pdbrc` script file.
* A :file:`.pdbrc` script file can contain ``continue`` and ``next`` commands
that continue debugging.
* The :class:`Pdb` class constructor now accepts a *nosigint* argument.
* new commands: ``l(list)``, ``ll(long list`` and ``source`` for
listing source code.
* new commands: ``display`` and ``undisplay`` for showing or hiding
the value of an expression if it has changed.
* new command: ``interact`` for starting an interactive interpreter containing
the global and local names found in the current scope.
* breakpoints can be cleared by breakpoint number
.. XXX: Create a new section for all changes relating to context managers.
.. XXX: Various ConfigParser changes
.. XXX: Mention urllib.parse changes
Issue 9873 (Nick Coghlan):