[Python-ideas] More alternate constructors for builtin type

[Cameron Simpson]

On 08May2019 00:18, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
>Steven D'Aprano wrote:
>>That suggests a possible pair of constructors:
>>    bytes.from_int(n)  -> equivalent to b'%d' % n
>>    bytes.ord(n)       -> equivalent to bytes((n,))
>
>I don't see how bytes.from_int(n) is any clearer about what it
>does than just bytes(n). If we're going to have named constructors,
>the names should indicate *how* the construction is being done,
>not just repeat the type of the argument.

How about from_size(n) and from_ord(n)? The former to make a NUL filled 
bytes of size n, the latter to make a single byte bytes with element 0 
having value n.

Preemptively one could argue for from_size having an optional fill 
value, default 0.  I think I'm -0 on that because I can't imagine a 
likely use case and it would slightly slow down every use.  I think I'd 
argue for a from_iter instead, to support an arbitrary fill 
pattern/sequence. That avoids slowing the common case and provides 
flexibility at the same time.

Cheers,
Cameron Simpson <cs at cskk.id.au>