Backwards Compatibility of Python versions

[Alex Martelli]

Kragen Sitaker wrote:
        ...
> and "x in somedict", which makes it impossible to have a class
> instance faithfully emulate both dictionaries and lists.  I'm not

No "make it impossible", because it ALREADY was impossible
before.  How "faithfully" am I emulating a dictionary if rebinding
x[-1] changes, say, x[5]?!  Yet that is part of what I MUST do
to "faithfully emulate" a list which has 6 items at this time.

> everyone.  And I don't expect Python to stop changing so fast just
> because *I* want it to.  I'm just hoping to add my voice to the chorus
> of "Slow down!"s.

And I hope otherwise.  If RedHat chooses to keep shipping 1.5.2
forever, I'll switch to Mandrake (actually, I _have_) -- it's RH's
funeral, not Python's:-).

Since the "Python 3000" idea of making one big clean break seems
to have been abandoned in favour of gradual stepwise compatible
changes (probably wise -- I can't judge on that, though), drawing
the process out through ten, or thirty, years, as you ask, would be
an utter disaster.  We need to reach a new stable plateau reasonably
fast, at least as badly as we need to keep backwards compatibility.

Right now we're clearly smack in the middle of it -- the worst of
times to start slowing down.  I suspect Guido has an excellent handle
on the balance of THIS tradeoff just like he has on the huge number
of tradeoffs that cumulatively make a language.


Alex