Tobiah <[EMAIL PROTECTED]> wrote: > Subject: Seemingly odd 'is' comparison.
Please put your question into the body of the message, not just the headers. >>>> print float(3.0) is float(3.0) > True >>>> print float(3.0 * 1.0) is float(3.0) > False >>>> > > > Thanks, > > Tobiah > Your values are already all floats so float() just returns its arguments. In other words you can omit it: >>> 3.0 is 3.0 True >>> 3.0 * 1.0 is 3.0 False 3.0 used twice in the same compilation unit is the same constant value used twice. 3.0 * 1.0 creates a new float value. Compare with: >>> n = 3.0 >>> n is 3.0 False Here two separate compilations result in two separate values. In general any immutable results of calculations which are the same may or may not share the same object and this can vary according to the version of Python or the phase of the moon. Only use 'is' when you actually care about object identity, don't use it for a shorthand for '=='. -- http://mail.python.org/mailman/listinfo/python-list
