In current, future and past documentation, the valid escape sequence \0
(equivalent to \x00) is missing from the list of possible escape
sequences in the documentation. As far as I can tell, it is not a case
covered by any of the other elements in the list, and is valid python
though I have only tested current (2.5.2) for it.

Current version can be found here: http://docs.python.org/ref/strings.html

The \0 falls under this case:

\ooo  	Character with octal value ooo

where the note says "As in Standard C, up to three octal digits are
accepted. "