This section of Plone content management system Developer Documentation is no longer under active maintenance. The section is included as the reference for older technologies (Plone 2.x, Plone 3.x). Some of the practices described in this documents may still work, but are not recommended to be used in your active Plone development. Use at your own risk.
If you arrived at this page by a web search we recommend to also see the Plone Developer Documentation front page .
Python 2.x does not make a clear distinction between:
Developers use these two formats interchangeably, because it is so easy and Python does not warn you about this.
However, it will only work as long as the input does not encounter any international, non-ASCII, characters. When 8-bit encoded string data and 16-bit raw Unicode string data gets mixed up, by being run through encoding first, really nasty things start to happen.
Plone's core contains a helper function which allows you to safely decode strings to unicode without fear of UnicodeDecodeException. Use this in your own code to decode unicode in the cases you are not sure if the input is 8-bit bytestrings or real unicode strings.
# -*- coding: utf-8 -*- from Products.CMFPlone.utils import safe_unicode foobar = safe_unicode("Ärrinmurrin taas on Plonea joku jättänyt dokumentoimatta")
Python has a system-wide setting to enforce encoding of all unicode input automatically to utf-8 when used as 8-bit string.
This is a wrong way to fix things and it will break other things. You have been warned.
There is also sitecustomization.py trick to set sys.setdefaultencoding("utf-8") on per-script basis
UnicodeEncodeError: 'ascii' codec can't encode character u'xe4' in position 4: ordinal not in range(128)
This is usually because you are trying to output/store unicode data using outdated methods, e.g.
print foo.encode("utf-8") # You are sure this is a unicode string
def safe_print(x): """ Do not die on bad input when doing debug prints """ if type(x) == str: print x else: print x.decode("utf-8")
This example will accept all string input and convert it to proper unicode strings.
if type(value) == str: # Ignore errors even if the string is not proper UTF-8 or has # broken marker bytes. # Python built-in function unicode() can do this. value = unicode(value, "utf-8", errors="ignore") else: # Assume the value object has proper __unicode__() method value = unicode(value)
Press CTRL+space / AltGr space on Linux to accidentally create it.
You can't see it. But it breaks everything.
Example to how to fix non-breaking space characters which have ended up in reStructuredText .txt files. This is Unicode character code A0.
# -*- coding: utf-8 -*- """ Fix non-breaking space characters which have ended up to reST .txt files. This is Unicode character code A0. Press CTRL+space / AltGr space on Linux to accidentally create it. E.g. as a sympton the following exception is raised if you try to upload Python egg:: File "/Library/Python/2.6/site-packages/docutils-0.6-py2.6.egg/docutils/parsers/rst/states.py", line 2621, in blank self.parent += self.literal_block() File "/Library/Python/2.6/site-packages/docutils-0.6-py2.6.egg/docutils/parsers/rst/states.py", line 2712, in literal_block literal_block = nodes.literal_block(data, data) File "/Library/Python/2.6/site-packages/docutils-0.6-py2.6.egg/docutils/nodes.py", line 810, in __init__ TextElement.__init__(self, rawsource, text, *children, **attributes) File "/Library/Python/2.6/site-packages/docutils-0.6-py2.6.egg/docutils/nodes.py", line 798, in __init__ textnode = Text(text) File "/Library/Python/2.6/site-packages/docutils-0.6-py2.6.egg/docutils/nodes.py", line 331, in __new__ return reprunicode.__new__(cls, data) UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 715: ordinal not in range(128) """ import os def fix(name): """ Fix a single .txt file """ input = open(name, "rt") text = input.read() input.close() text = text.decode("utf-8") # Show if we get bad hits for c in text: if c == u"\xa0": print "Ufff" text = text.replace(u"\xa0", u" ") text = text.encode("utf-8") output = open(name, "wt") output.write(text) output.close() # Process all .txt files in the # current folder for f in os.listdir(os.getcwd()): if f.endswith(".txt"): fix(f)
The source code of this file is hosted on GitHub. Everyone can update and fix errors in this document with few clicks - no downloads needed.
For basic information about updating this manual and Sphinx format please see Writing and updating the manual guide.