Unicode HOWTO
*****************
-:Release: 1.02
+:Release: 1.03
-This HOWTO discusses Python's support for Unicode, and explains various problems
-that people commonly encounter when trying to work with Unicode.
+This HOWTO discusses Python 2.x's support for Unicode, and explains
+various problems that people commonly encounter when trying to work
+with Unicode. (This HOWTO has not yet been updated to cover the 3.x
+versions of Python.)
Introduction to Unicode
=======================
4. Many Internet standards are defined in terms of textual data, and can't
handle content with embedded zero bytes.
-Generally people don't use this encoding, instead choosing other encodings that
-are more efficient and convenient.
+Generally people don't use this encoding, instead choosing other
+encodings that are more efficient and convenient. UTF-8 is probably
+the most commonly supported encoding; it will be discussed below.
Encodings don't have to handle every possible Unicode character, and most
encodings don't. For example, Python's default encoding is the 'ascii'
<http://en.wikipedia.org/wiki/UTF-8>, for example.
-Python's Unicode Support
-========================
+Python 2.x's Unicode Support
+============================
Now that you've learned the rudiments of Unicode, we can look at Python's
Unicode features.
>>> unicode('\x80abc', errors='ignore')
u'abc'
-Encodings are specified as strings containing the encoding's name. Python 2.4
+Encodings are specified as strings containing the encoding's name. Python 2.7
comes with roughly 100 different encodings; see the Python Library Reference at
:ref:`standard-encodings` for a list. Some encodings
have multiple names; for example, 'latin-1', 'iso_8859_1' and '8859' are all
When you run it with Python 2.4, it will output the following warning::
- amk:~$ python p263.py
+ amk:~$ python2.4 p263.py
sys:1: DeprecationWarning: Non-ASCII character '\xe9'
in file p263.py on line 2, but no encoding declared;
see http://www.python.org/peps/pep-0263.html for details
+Python 2.5 and higher are stricter and will produce a syntax error::
+
+ amk:~$ python2.5 p263.py
+ File "/tmp/p263.py", line 2
+ SyntaxError: Non-ASCII character '\xc3' in file /tmp/p263.py
+ on line 2, but no encoding declared; see
+ http://www.python.org/peps/pep-0263.html for details
+
Unicode Properties
------------------
Version 1.02: posted August 16 2005. Corrects factual errors.
+Version 1.03: posted June 20 2010. Notes that Python 3.x is not covered,
+and that the HOWTO only covers 2.x.
+
+.. comment Describe Python 3.x support (new section? new document?)
.. comment Additional topic: building Python w/ UCS2 or UCS4 support
.. comment Describe obscure -U switch somewhere?
.. comment Describe use of codecs.StreamRecoder and StreamReaderWriter