[Python-ideas] Stop displaying elements of bytes objects as printable ASCII characters in CPython 3

[Nick Coghlan]

On 11 Sep 2014 06:30, "Chris Lasher" <chris.lasher at gmail.com> wrote:
>
> Put yourself in the shoes of a beginner.

We often compromise the beginner experience for backwards compatibility
reasons, or to provide a better developer experience in the long run (cf.
changing print from a statement to a builtin function).

In this case, I *agree* the current behaviour is confusing, since it
recreates some of the old "is it binary or is it text?" confusion that was
more endemic in Python 2.

In Python 3, "bytes" is still a hybrid type that can hold:
* arbitrary binary data
* binary data that contains ASCII segments

A pure teaching language wouldn't make that compromise. Python 3 isn't a
pure teaching language though - it's a pragmatic professional programming
language that is *also* useful for teaching.

The problem is that for a lot of data it is *genuinely ambiguous* as to
which of those it actually is (and it may change at runtime depending on
the specific nature of the data).

Both the default repr and the literal form assume the "binary data ASCII
compatible segments", which aligns with the behaviour of the Python 2 str
type. That isn't going to change in Python, especially since we actually
*did* try it for a while (prior to the 3.0 release) and really didn't like
it.

However, as others have noted, making it easier to get a pure hex
representation is likely worth doing. There are lots of ways of doing that
currently, but none that really qualify as "obvious".

Cheers,
Nick.
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