[PYTHON-CRYPTO] Comments on PEP 247 (Hashing)

[Rich Salz]

> > 1.  Why is there a new method; why isn't the classic
> > constructor good enough?  The PEP needs to justify this.
>
> That way you don't have to worry about what the
> constructor is called.

This seems a weak argument.  My code already has to know what module to
import:
        from hash import SHA1
        s = SHA1.SHA1()
as opposed to
        from hash import SHA1
        s = SHA1.new()
or
        from hash import SHA1 as HASH
        s = HASH.new()

The first is the standard pythnon way to do things, the second shows no
gain for being non-standard, and the third seems like risky code.  Am I
missing something?

I think the PEP should (a) justify why new() is defined; and (b) define
standard Python constructor use.

> Maybe instead:
> new(str="")
> new(key, str="")
>
> Having the initial string is useful:
> digest = sha.new(str).digest()

If update() (or write() :) returned self, you could do
        digest = sha1.sha1().update(str).digest()

I don't care, as long as the initial text is an explicit keyword. :
        /r$
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