Manually create a hex value

[Stas43]

the \x is an escape character which says take the following as hexadecimal number
once separated from each other, the \x by itself fails because there is no value immediately following
a = '' + '\xcf'
would work.

Of course, your option works. And how does it differ from my version in the first post ... a = '\xcf' ...?
I want to collect! variable b from two different lines:
'\x' and 'cf' but Python doesn't understand this!