[Python-Dev] The -U flag (original) (raw)

M.-A. Lemburg mal@lemburg.com
Mon, 14 Oct 2002 09:37:06 +0200

Guido van Rossum wrote:

Since Python allows Unicode strings in sys.path, we are making progress on getting -U to work. When entering interactive mode, the stumbling block is

_idmap = '' for i in range(256): idmap = idmap + chr(i) del i Here, idmap is initialized with a Unicode string, and the chr(i) results are promoted to Unicode, which eventually causes a UnicodeErorr when you get past 127. The work-around would be to write _idmap = str('') for i in range(256): idmap = idmap + chr(i) del i With that, we can enter interactive mode in python -U. Is such a change acceptable? Only with a comment that explains it -- otherwise the next person looking at the code will remove it.

Wouldn't the following be faster ?

l = map(chr, range(256)) _idmap = str('').join(l) del l

But didn't we at one point conclude that -U was never gonna work? And wasn't that why it's no longer documented?

I don't remember such a conclusion. The reason for having -U in the first place was to test the Python standard lib for being able to handle Unicode seemlessly. Obviously we are still far from having reached that point, but it's a good way of being able to test the compatibility.

It's no longer documented to reduce the number of bug-reports we get for it. It was never meant to be used by users (at this point), just by developers.

-- Marc-Andre Lemburg CEO eGenix.com Software GmbH

eGenix.com -- Makers of the Python mx Extensions: mxDateTime,mxODBC,... Python Consulting: http://www.egenix.com/ Python Software: http://www.egenix.com/files/python/