A few questiosn about encoding

[Nick the Gr33k]

On 14/6/2013 4:58 μμ, Nick the Gr33k wrote:
> On 14/6/2013 1:14 μμ, Cameron Simpson wrote:
>> Normally a character in a b'...' item represents the byte value
>> matching the character's Unicode ordinal value.
>
> The only thing that i didn't understood is this line.
> First please tell me what is a byte value
>
>> \x1b is a sequence you find inside strings (and "byte" strings, the
>> b'...' format).
>
> \x1b is a character(ESC) represented in hex format
>
> b'\x1b' is a byte object that represents what?
>
>
>  >>> chr(27).encode('utf-8')
> b'\x1b'
>
>  >>> b'\x1b'.decode('utf-8')
> '\x1b'
>
> After decoding it gives the char ESC in hex format
> Shouldn't it result in value 27 which is the ordinal of ESC ?
>
>  > No, I mean conceptually, there is no difference between a code-point
>  > and its ordinal value. They are the same thing.
>
> Why Unicode charset doesn't just contain characters, but instead it
> contains a mapping of (characters <--> ordinals) ?
>
> I mean what we do is to encode a character like chr(65).encode('utf-8')
>
> What's the reason of existence of its corresponding ordinal value since
> it doesn't get involved into the encoding process?
>
> Thank you very much for taking the time to explain.

Can someone please explain these questions too?

-- 
What is now proved was at first only imagined!