unicode "em space" in regex

[Reinhold Birkenfeld]

Xah Lee wrote:

> "Regular expression pattern strings may not contain null bytes, but can
> specify the null byte using the \number notation."
> 
> What is meant by null bytes here? Unprintable chars?? and the "\number"
> is meant to be decimal? and in what encoding?

The null byte is a byte with the integer value 0. Difficult, isn't it.

The \number notation is, as you could read in http://docs.python.org/ref/strings.html,
octal.

Reinhold