常見Python問答集
****************


常見資訊
========


什麼是Python?
-------------

Python is an interpreted, interactive, object-oriented programming
language.  It incorporates modules, exceptions, dynamic typing, very
high level dynamic data types, and classes.  Python combines
remarkable power with very clear syntax. It has interfaces to many
system calls and libraries, as well as to various window systems, and
is extensible in C or C++.  It is also usable as an extension language
for applications that need a programmable interface. Finally, Python
is portable: it runs on many Unix variants, on the Mac, and on Windows
2000 and later.

To find out more, start with Python 教學.  The Beginner's Guide to
Python links to other introductory tutorials and resources for
learning Python.


什麼是Python軟體基金會?
-----------------------

Python軟體基金會是一個獨立非營利性組織，並且擁有Python版本2.1 與更新的
版本版權。Python軟體基金會的任務在於精進相關於Python 程式語言撰寫於開
放原始碼技術，而且宣傳使用Python 。Python軟體基金會網址
:https://www.python.org/psf/

在美國捐款給Python軟體基金會是免稅的，如果你使用Python而且發現很好用，
請貢獻捐款到Python軟體基金會捐款頁面
<https://www.python.org/psf/donations/>


當使用Python時有任何版權限制嗎?
-------------------------------

You can do anything you want with the source, as long as you leave the
copyrights in and display those copyrights in any documentation about
Python that you produce.  If you honor the copyright rules, it's OK to
use Python for commercial use, to sell copies of Python in source or
binary form (modified or unmodified), or to sell products that
incorporate Python in some form.  We would still like to know about
all commercial use of Python, of course.

請看Python軟體基金會的授權頁面<https://www.python.org/psf/license/>有
更完整的授權說明

The Python logo is trademarked, and in certain cases permission is
required to use it.  Consult the Trademark Usage Policy for more
information.


為什麼Python被創造出來
----------------------

Guido van Rossum寫下這篇"非常長"的簡述說明Python的由來

   I had extensive experience with implementing an interpreted
   language in the ABC group at CWI, and from working with this group
   I had learned a lot about language design.  This is the origin of
   many Python features, including the use of indentation for
   statement grouping and the inclusion of very-high-level data types
   (although the details are all different in Python).

   I had a number of gripes about the ABC language, but also liked
   many of its features.  It was impossible to extend the ABC language
   (or its implementation) to remedy my complaints -- in fact its lack
   of extensibility was one of its biggest problems.  I had some
   experience with using Modula-2+ and talked with the designers of
   Modula-3 and read the Modula-3 report. Modula-3 is the origin of
   the syntax and semantics used for exceptions, and some other Python
   features.

   I was working in the Amoeba distributed operating system group at
   CWI.  We needed a better way to do system administration than by
   writing either C programs or Bourne shell scripts, since Amoeba had
   its own system call interface which wasn't easily accessible from
   the Bourne shell.  My experience with error handling in Amoeba made
   me acutely aware of the importance of exceptions as a programming
   language feature.

   It occurred to me that a scripting language with a syntax like ABC
   but with access to the Amoeba system calls would fill the need.  I
   realized that it would be foolish to write an Amoeba-specific
   language, so I decided that I needed a language that was generally
   extensible.

   During the 1989 Christmas holidays, I had a lot of time on my hand,
   so I decided to give it a try.  During the next year, while still
   mostly working on it in my own time, Python was used in the Amoeba
   project with increasing success, and the feedback from colleagues
   made me add many early improvements.

   In February 1991, after just over a year of development, I decided
   to post to USENET.  The rest is in the "Misc/HISTORY" file.


什麼是Python擅長的事情
----------------------

Python是高階語言及一般任何用途都可以使用的語言，可以用來解決不同的問題

The language comes with a large standard library that covers areas
such as string processing (regular expressions, Unicode, calculating
differences between files), Internet protocols (HTTP, FTP, SMTP, XML-
RPC, POP, IMAP, CGI programming), software engineering (unit testing,
logging, profiling, parsing Python code), and operating system
interfaces (system calls, filesystems, TCP/IP sockets).  Look at the
table of contents for Python 標準函式庫 (Standard Library) to get an
idea of what's available.  A wide variety of third-party extensions
are also available.  Consult the Python Package Index to find packages
of interest to you.


How does the Python version numbering scheme work?
--------------------------------------------------

Python versions are numbered A.B.C or A.B.  A is the major version
number -- it is only incremented for really major changes in the
language.  B is the minor version number, incremented for less earth-
shattering changes.  C is the micro-level -- it is incremented for
each bugfix release.  See **PEP 6** for more information about bugfix
releases.

Not all releases are bugfix releases.  In the run-up to a new major
release, a series of development releases are made, denoted as alpha,
beta, or release candidate.  Alphas are early releases in which
interfaces aren't yet finalized; it's not unexpected to see an
interface change between two alpha releases. Betas are more stable,
preserving existing interfaces but possibly adding new modules, and
release candidates are frozen, making no changes except as needed to
fix critical bugs.

Alpha, beta and release candidate versions have an additional suffix.
The suffix for an alpha version is "aN" for some small number N, the
suffix for a beta version is "bN" for some small number N, and the
suffix for a release candidate version is "cN" for some small number
N.  In other words, all versions labeled 2.0aN precede the versions
labeled 2.0bN, which precede versions labeled 2.0cN, and *those*
precede 2.0.

You may also find version numbers with a "+" suffix, e.g. "2.2+".
These are unreleased versions, built directly from the CPython
development repository.  In practice, after a final minor release is
made, the version is incremented to the next minor version, which
becomes the "a0" version, e.g. "2.4a0".

See also the documentation for "sys.version", "sys.hexversion", and
"sys.version_info".


我如何拿到Python的原始碼
------------------------

The latest Python source distribution is always available from
python.org, at https://www.python.org/downloads/.  The latest
development sources can be obtained at
https://github.com/python/cpython/.

The source distribution is a gzipped tar file containing the complete
C source, Sphinx-formatted documentation, Python library modules,
example programs, and several useful pieces of freely distributable
software.  The source will compile and run out of the box on most UNIX
platforms.

Consult the Getting Started section of the Python Developer's Guide
for more information on getting the source code and compiling it.


如何取得Python的相關文件
------------------------

The standard documentation for the current stable version of Python is
available at https://docs.python.org/3/.  PDF, plain text, and
downloadable HTML versions are also available at
https://docs.python.org/3/download.html.

The documentation is written in reStructuredText and processed by the
Sphinx documentation tool.  The reStructuredText source for the
documentation is part of the Python source distribution.


我從來沒寫過程式，有沒有Python的教學
------------------------------------

There are numerous tutorials and books available.  The standard
documentation includes Python 教學.

Consult the Beginner's Guide to find information for beginning Python
programmers, including lists of tutorials.


有沒有新手的群組或是郵件群組討論Python
--------------------------------------

There is a newsgroup, *comp.lang.python*, and a mailing list, python-
list.  The newsgroup and mailing list are gatewayed into each other --
if you can read news it's unnecessary to subscribe to the mailing
list. *comp.lang.python* is high-traffic, receiving hundreds of
postings every day, and Usenet readers are often more able to cope
with this volume.

Announcements of new software releases and events can be found in
comp.lang.python.announce, a low-traffic moderated list that receives
about five postings per day.  It's available as the python-announce
mailing list.

More info about other mailing lists and newsgroups can be found at
https://www.python.org/community/lists/.


How do I get a beta test version of Python?
-------------------------------------------

Alpha and beta releases are available from
https://www.python.org/downloads/.  All releases are announced on the
comp.lang.python and comp.lang.python.announce newsgroups and on the
Python home page at https://www.python.org/; an RSS feed of news is
available.

You can also access the development version of Python through Git.
See The Python Developer's Guide for details.


How do I submit bug reports and patches for Python?
---------------------------------------------------

To report a bug or submit a patch, please use the Roundup installation
at https://bugs.python.org/.

You must have a Roundup account to report bugs; this makes it possible
for us to contact you if we have follow-up questions.  It will also
enable Roundup to send you updates as we act on your bug. If you had
previously used SourceForge to report bugs to Python, you can obtain
your Roundup password through Roundup's password reset procedure.

For more information on how Python is developed, consult the Python
Developer's Guide.


Are there any published articles about Python that I can reference?
-------------------------------------------------------------------

It's probably best to cite your favorite book about Python.

最早討論Python的文章在1991年，但現在來看已經有點過時

   Guido van Rossum and Jelke de Boer, "Interactively Testing Remote
   Servers Using the Python Programming Language", CWI Quarterly,
   Volume 4, Issue 4 (December 1991), Amsterdam, pp 283--303.


有沒有關於Python的書
--------------------

是的已經有很多書出版，可以參考這個連結的參考書目
https://wiki.python.org/moin/PythonBooks

你也可以上網搜尋網路書店關鍵字為"Python"，但不要使用"Monty Python"當作
關鍵字。或者可以搜尋"Python"和"語言"


www.python.org 這個非營利組織位於哪裡
-------------------------------------

The Python project's infrastructure is located all over the world.
www.python.org is graciously hosted by Rackspace, with CDN caching
provided by Fastly.  Upfront Systems hosts bugs.python.org.  Many
other Python services like the Wiki are hosted by Oregon State
University Open Source Lab.


為什麼要取名為Python
--------------------

When he began implementing Python, Guido van Rossum was also reading
the published scripts from "Monty Python's Flying Circus", a BBC
comedy series from the 1970s.  Van Rossum thought he needed a name
that was short, unique, and slightly mysterious, so he decided to call
the language Python.


我需要喜歡蒙提·派森的飛行馬戲團這個節目嗎
-----------------------------------------

不需要，但它有幫助 :)


Python在真實世界
================


Python穩定性如何
----------------

非常穩定。自從1991年開始大約每隔6到18個月會釋出更新版，而且看起來會繼
續更新下去。現在大約18個月會有主要的更新

The developers issue "bugfix" releases of older versions, so the
stability of existing releases gradually improves.  Bugfix releases,
indicated by a third component of the version number (e.g. 3.5.3,
3.6.2), are managed for stability; only fixes for known problems are
included in a bugfix release, and it's guaranteed that interfaces will
remain the same throughout a series of bugfix releases.

The latest stable releases can always be found on the Python download
page.  There are two production-ready version of Python: 2.x and 3.x,
but the recommended one at this times is Python 3.x. Although Python
2.x is still widely used, it will not be maintained after January 1,
2020. Python 2.x was known for having more third-party libraries
available, however, by the time of this writing, most of the widely
used libraries support Python 3.x, and some are even dropping the
Python 2.x support.


有多少人使用Python
------------------

大約有超過一萬個使用者，實際上有多少人是很難準確的估算

Python is available for free download, so there are no sales figures,
and it's available from many different sites and packaged with many
Linux distributions, so download statistics don't tell the whole story
either.

The comp.lang.python newsgroup is very active, but not all Python
users post to the group or even read it.


有沒有任何重要的案子使用Python完成開發
--------------------------------------

See https://www.python.org/about/success for a list of projects that
use Python. Consulting the proceedings for past Python conferences
will reveal contributions from many different companies and
organizations.

High-profile Python projects include the Mailman mailing list manager
and the Zope application server.  Several Linux distributions, most
notably Red Hat, have written part or all of their installer and
system administration software in Python.  Companies that use Python
internally include Google, Yahoo, and Lucasfilm Ltd.


對於程式開發者Python對於未來有什麼期待
--------------------------------------

See https://www.python.org/dev/peps/ for the Python Enhancement
Proposals (PEPs). PEPs are design documents describing a suggested new
feature for Python, providing a concise technical specification and a
rationale.  Look for a PEP titled "Python X.Y Release Schedule", where
X.Y is a version that hasn't been publicly released yet.

New development is discussed on the python-dev mailing list.


Is it reasonable to propose incompatible changes to Python?
-----------------------------------------------------------

In general, no.  There are already millions of lines of Python code
around the world, so any change in the language that invalidates more
than a very small fraction of existing programs has to be frowned
upon.  Even if you can provide a conversion program, there's still the
problem of updating all documentation; many books have been written
about Python, and we don't want to invalidate them all at a single
stroke.

Providing a gradual upgrade path is necessary if a feature has to be
changed. **PEP 5** describes the procedure followed for introducing
backward-incompatible changes while minimizing disruption for users.


Python對於入門的程式設計者而言是否為好的程式語言
------------------------------------------------

是的

It is still common to start students with a procedural and statically
typed language such as Pascal, C, or a subset of C++ or Java.
Students may be better served by learning Python as their first
language.  Python has a very simple and consistent syntax and a large
standard library and, most importantly, using Python in a beginning
programming course lets students concentrate on important programming
skills such as problem decomposition and data type design.  With
Python, students can be quickly introduced to basic concepts such as
loops and procedures.  They can probably even work with user-defined
objects in their very first course.

For a student who has never programmed before, using a statically
typed language seems unnatural.  It presents additional complexity
that the student must master and slows the pace of the course.  The
students are trying to learn to think like a computer, decompose
problems, design consistent interfaces, and encapsulate data.  While
learning to use a statically typed language is important in the long
term, it is not necessarily the best topic to address in the students'
first programming course.

Many other aspects of Python make it a good first language.  Like
Java, Python has a large standard library so that students can be
assigned programming projects very early in the course that *do*
something.  Assignments aren't restricted to the standard four-
function calculator and check balancing programs.  By using the
standard library, students can gain the satisfaction of working on
realistic applications as they learn the fundamentals of programming.
Using the standard library also teaches students about code reuse.
Third-party modules such as PyGame are also helpful in extending the
students' reach.

Python's interactive interpreter enables students to test language
features while they're programming.  They can keep a window with the
interpreter running while they enter their program's source in another
window.  If they can't remember the methods for a list, they can do
something like this:

   >>> L = []
   >>> dir(L) 
   ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
   '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
   '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__',
   '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__',
   '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__',
   '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__',
   '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear',
   'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
   'reverse', 'sort']
   >>> [d for d in dir(L) if '__' not in d]
   ['append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

   >>> help(L.append)
   Help on built-in function append:

   append(...)
       L.append(object) -> None -- append object to end

   >>> L.append(1)
   >>> L
   [1]

With the interpreter, documentation is never far from the student as
they are programming.

There are also good IDEs for Python.  IDLE is a cross-platform IDE for
Python that is written in Python using Tkinter.  PythonWin is a
Windows-specific IDE. Emacs users will be happy to know that there is
a very good Python mode for Emacs.  All of these programming
environments provide syntax highlighting, auto-indenting, and access
to the interactive interpreter while coding.  Consult the Python wiki
for a full list of Python editing environments.

If you want to discuss Python's use in education, you may be
interested in joining the edu-sig mailing list.
