Yet another unicode WTF

[Ned Deily]

In article <rNOSPAMon-E7E08B.18181804062009 at news.gha.chartermi.net>,
 Ron Garret <rNOSPAMon at flownet.com> wrote:
> Python 2.6.2 on OS X 10.5.7:
> 
> [ron at mickey:~]$ echo $LANG
> en_US.UTF-8
> [ron at mickey:~]$ cat frob.py 
> #!/usr/bin/env python
> print u'\u03BB'
> 
> [ron at mickey:~]$ ./frob.py 
> ª
> [ron at mickey:~]$ ./frob.py > foo
> Traceback (most recent call last):
>   File "./frob.py", line 2, in <module>
>     print u'\u03BB'
> UnicodeEncodeError: 'ascii' codec can't encode character u'\u03bb' in 
> position 0: ordinal not in range(128)
> 
> 
> (That's supposed to be a small greek lambda, but I'm using a 
> brain-damaged news reader that won't let me set the character encoding.  
> It shows up correctly in my terminal.)
> 
> According to what I thought I knew about unix (and I had fancied myself 
> a bit of an expert until just now) this is impossible.  Python is 
> obviously picking up a different default encoding when its output is 
> being piped to a file, but I always thought one of the fundamental 
> invariants of unix processes was that there's no way for a process to 
> know what's on the other end of its stdout.
> 
> Clues appreciated.  Thanks.

$ python2.6 -c 'import sys; print sys.stdout.encoding, \
 sys.stdout.isatty()'
UTF-8 True
$ python2.6 -c 'import sys; print sys.stdout.encoding, \
 sys.stdout.isatty()' > foo ; cat foo
None False

-- 
 Ned Deily,
 nad at acm.org