On Tue, Apr 28, 2009 at 3:39 PM, Marius Gedminas
<marius@xxxxxxxxx> wrote
>>> 1.8 misc
>>> ======================
>>> 1.8.1 support iter protocol
>>> 1.8.2 str(v) -> "[x, y, z]"
>>> 1.8.3 repr(v) -> "Vec<x, y, z>"
>>
>> Most objects have the same output for str() and repr(). Why do you
>> differ here?
>
> with repr I wanted to make explicitly clear that this is not a list but I
> thought that the normal str() would look nicer that way. what would you
> suggest? "[x, y, z]" for both (or "(x, y, z)" if we choose to make
> vectors immutable) or "Vector3d<x, y, z>"?
I'm +0.95 for distinct __str__ and __repr__. str is what you show your
users and should be short and clear, while repr is what you give the
programmers who're debugging and therefore exact types matter.
As far as I understand it, __repr__ is supposed to give you a representation that can reproduce an equivalent object. In other words, eval(repr(ob)) == ob. I'm not sure if this property is true in all cases where __repr__ has been used, but it holds for python standard types. I think it's more of a consideration than a full on standard. Still, I would prefer then to have the __repr__ be "Vector3d(x, y, z)" if that is in fact the constructor of a vector3d. Of course this doesn't matter much.