Beni Cherniavsky wrote:
On Mon, 2005-10-24 at 20:24 -0700, Scott David Daniels wrote:
Of course, the proper way to compare object identity is not the
__low_level__ `id()` function but the ``is`` operator:
(math.pi + 1.0) is (29. / 7.)
False
int('99') is int('99') # small integer
On Mon, 2005-10-24 at 20:24 -0700, Scott David Daniels wrote:
With CPython, expressions, once used and dereferenced, recycle their
objects. If you don't hold a reference to the value created by
calculating the log of pi, it will get recycled once id is done
with is arg. The available storage
Kirby
PS: since you've been studying subclassing primitive types using __new__,
maybe you could show us a user-defined floating point type that reports
two numbers equal if their absolute value difference is less than e.
Anyone?
Like this I guess:
class Fuzzy(float):
tol =
Kirby Urner wrote:
Kirby
PS: since you've been studying subclassing primitive types using __new__,
maybe you could show us a user-defined floating point type that reports
two numbers equal if their absolute value difference is less than e.
Anyone?
Fuzzy redone a breath:
class Fuzzy(float):
Here's the problem:
Your notion of equality is not transitive. That's tough -- it
invalidates the assumptions of the float type (and all basic types).
Also, you didn't tweak hash, so a dictionary with these things in them
would not find entries that turn out to be equal.
--Scott David
Arthur wrote:
Scott David Daniels wrote:
...
Getting one's arms around all the practical implications of these issues
related to mutable, immutable - understanding when one should want to
retain object identity, and when one should want to break it, the full
implications of these
Going into my new presentation manager materials (perhaps using the same
Pygame engine I used at OSCON, but as a general purpose module, i.e. not
tied up in that specific content) is the distinction between two kinds of
Python: Python and __Python__.
You really get to a new level with Python
