[Python-Dev] \u and \U escapes in raw unicode string literals (original) (raw)

Thomas Heller theller at ctypes.org
Fri May 11 13:05:05 CEST 2007

M.-A. Lemburg schrieb:

On 2007-05-11 07:52, Martin v. Löwis wrote:

This is what prompted my question, actually: in Py3k, in the str/unicode unification branch, r"\u1234" changes meaning: before the unification, this was an 8-bit string, where the \u was not special, but now it is a unicode string, where \u is special.

That is true for non-raw strings also: the meaning of "\u1234" also changes. However, traditionally, there was no escaping mechanism in raw strings in Python, and I feel that this is a good principle, because it is easy to learn (if you leave out the detail that \ can't be the last character in a raw string - which should get fixed also, IMO). So I think in Py3k, "\u1234" should continue to be a string with 6 characters. Otherwise, people will complain that os.stat(r"c:\windows\system32\user32.dll") fails. Telling them to write os.stat(r"c:\windows\system32\u005Cuser32.dll") will just cause puzzled faces. Using double backslashes won't cause that reaction: os.stat("c:\windows\system32\user32.dll")

Sure. But I want to use raw strings for Windows path names; it's much easier to type.

Also note that Windows is smart enough nowadays to parse the good old Unix forward slash:

os.stat("c:/windows/system32/user32.dll")

In my opinion this is a windows bug and not a features. Especially because there are Windows api functions (the shell functions, IIRC) that do NOT accept forward slashes.

Would you say that *nix is dumb because it doesn't parse "\usr\include"?

Windows path names are one of the two primary applications of raw strings (the other being regexes).

Thomas

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