shutil.copy2(file, dest) fails when dest has unicode characters:

[2011-04-02 17:19:54 adam@adam-laptop ~/personal :) ]$ python
Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) 
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import glob
>>> import shutil
>>> files=glob.glob('*.ods')
>>> for file in files:
...     shutil.copy2(file, 'א') # This works, but:
...
>>> for file in files:
...     shutil.copy2(file, u'א')
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "/usr/lib/python2.6/shutil.py", line 98, in copy2
    dst = os.path.join(dst, os.path.basename(src))
  File "/usr/lib/python2.6/posixpath.py", line 70, in join
    path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd7 in position 1: ordinal not in range(128)


See discussion here: http://stackoverflow.com/questions/5523373/python-how-to-move-a-file-with-unicode-filename-to-a-unicode-folder/5523385#5523385

The problem here is that you are mixing byte strings and unicode.
glob.glob('*.ods') returns a list of strings, so in shutil.copy2(file, 'א') you are passing two byte strings and everything works fine.
In shutil.copy2(file, u'א') instead, file is a byte string, and u'א' is unicode, so the copy fails.
If you want to use u'א', you can pass u'*.ods' to glob.glob() in order to get a list of unicode strings from there too.

Don't you think that shutil should be able to handle mixed data types, for example byte string as file name and unicode destination directory? This is, in my opinion, a very common scenario.

Would you consider converting all arguments to Unicode?

I should have added that both 'א' and u'א' work as long as the file names in the list returned by glob() are ASCII: if u'א' is used they are simply coerced to unicode.
If there are non-ASCII file names in the glob() list, the copy fails because Python 2 tries to coerce the name to unicode decoding it implicitly with the 'ascii' codec, and that fails.

Don't you think it should be changed in Python 2.x, so that the ASCII filename will be automatically converted to to Unicode?

The ASCII filename is already converted to unicode, but in your case the program was most likely failing with some non-ASCII filename.

Do you think it should be fixed at the module level?

Mixing byte and unicode strings should always be avoided, because the implicit coercion to unicode works only if the byte strings contains only ASCII, and fails otherwise.
Several modules -- including shutil, glob, and os.path -- have API that work with both byte and unicode strings, but fail when you mix the two:
>>> os.path.join('א', 'א')  # both byte strings -- works
'\xd7\x90/\xd7\x90'
>>> os.path.join(u'א', u'א')  # both unicode -- works
u'\u05d0/\u05d0'
>>> os.path.join('a', u'א')  # mixed, ASCII-only byte string -- works
u'a/\u05d0'

>>> os.path.join(u'א', 'א')  # mixed, non-ASCII -- fails
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/posixpath.py", line 70, in join
    path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd7 in position 1: ordinal not in range(128)
>>> os.path.join('א', u'א')  # mixed, non-ASCII -- fails
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/posixpath.py", line 70, in join
    path += '/' + b
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd7 in position 0: ordinal not in range(128)
>>>