William O'Higgins Witteman wrote:
>> for thing in os.walk(u'.'):
>>
>> instead of:
>>
>> for thing in os.walk('.'):
>
> This is a good thought, and the crux of the problem. I pull the
> starting directories from an XML file which is UTF-8, but by the time it
> hits my program, because there are no extended characters in the
> starting path, os.walk assumes ascii. So, I recast the string as UTF-8,
> and I get UTF-8 output. The problem happens further down the line.
>
> I get a list of paths from the results of os.walk, all in UTF-8, but not
> identified as such. If I just pass my list to other parts of the
> program it seems to assume either ascii or UTF-8, based on the
> individual list elements. If I try to cast the whole list as UTF-8, I
> get an exception because it is assuming ascii and receiving UTF-8 for
> some list elements.
FWIW, I'm pretty sure you are confusing Unicode strings and UTF-8
strings, they are not the same thing. A Unicode string uses 16 bits to
represent each character. It is a distinct data type from a 'regular'
string. Regular Python strings are byte strings with an implicit
encoding. One possible encoding is UTF-8 which uses one or more bytes to
represent each character.
Some good reading on Unicode and utf-8:
http://www.joelonsoftware.com/articles/Unicode.html
http://effbot.org/zone/unicode-objects.htm
If you pass a unicode string (not utf-8) to os.walk(), the resulting
lists will also be unicode.
Again, it would be helpful to see the code that is getting the error.
> I suspect that my program will have to make sure to recast all
> equivalent-to-ascii strings as UTF-8 while leaving the ones that are
> already extended alone.
It is nonsense to talk about 'recasting' an ascii string as UTF-8; an
ascii string is *already* UTF-8 because the representation of the
characters is identical. OTOH it makes sense to talk about converting an
ascii string to a unicode string.
Kent
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