I was doing some work today, and came across an issue where something “looked funny”. I had been interpreting some string data as utf-8, and checking the encoded form. The data was coming from ldap (Specifically, Active Directory) via python-ldap. No surprises there.
So I came upon the byte sequence ‘\xe3\x80\xb0’ a few times, which, when decoded as utf-8, is unicode codepoint 3030 (wavy dash). I need the string data in utf-16, so naturally I converted it via .encode(‘utf-16’). Unfortunately, it seems python doesn’t like this character:
D:\> python
Python 2.6.4 (r264:75708, Oct 26 2009, 08:23:19) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> u"\u3030"
u'\u3030'
>>> u"\u3030".encode("utf-8")
'\xe3\x80\xb0'
>>> u"\u3030".encode("utf-16-le")
'00'
>>> u"\u3030".encode("utf-16-be")
'00'
>>> '\xe3\x80\xb0'.decode('utf-8')
u'\u3030'
>>> '\xe3\x80\xb0'.decode('utf-8').encode('utf-16')
'\xff\xfe00'
>>> '\xe3\x80\xb0'.decode('utf-8').encode('utf-16-le').decode('utf-8')
u'00'
It seems IronPython isn’t a fan either:
D:\ipy
IronPython 2.6 Beta 2 (2.6.0.20) on .NET 2.0.50727.3053
Type "help", "copyright", "credits" or "license" for more information.
>>> u"\u3030"
u'\u3030'
>>> u"\u3030".encode('utf-8')
u'\xe3\x80\xb0'
>>> u"\u3030".encode('utf-16-le')
'00'
If somebody could tell me what, exactly, is going on here, it’d be much appreciated.
This seems to be the correct behaviour. The character u’\u3030′ when encoded in UTF-16 is the same as the encoding of ’00’ in UTF-8. It looks strange, but it’s correct.
The ‘\xff\xfe’ you can see is just a Byte Order Mark.
Are you sure you want a wavy dash, and not some other character? If you were hoping for a different character then it might be because it had already been misencoded before entering your application.